WO2018121465A1

WO2018121465A1 - Diphosphino metallic complexes, methods of making and using

Info

Publication number: WO2018121465A1
Application number: PCT/CN2017/118205
Authority: WO
Inventors: Chi-Ming Che; Mehmood FAISAL; Chun Nam LOK
Original assignee: University of Hong Kong HKU
Current assignee: University of Hong Kong HKU
Priority date: 2016-12-28
Filing date: 2017-12-25
Publication date: 2018-07-05
Anticipated expiration: 2019-06-28
Also published as: CN110139869A; CN110139869B

Abstract

Diphosphino metallic complexes, methods of making and using are described. The complexes display cytotoxicity against a panel of cancer cell lines, and optionally display luminescent properties. They have improved solubility and are stable against hydrolysis in physiologically reducing conditions. In some aspects, the complexes are iridium (III) diphosphine complexes. The compounds and pharmaceutical compositions thereof can be administered to a subject in need thereof to treat a host of diseases and disorders including but not limited to, proliferative disorders such as cancer.

Description

DIPHOSPHINO METALLIC COMPLEXES, METHODS OF MAKING AND USING

FIELD OF THE INVENTION

The invention is in the field of organometallic complexes, particularly cyclometalated diphosphino-organometallic complexes having anti-cancer properties, and with increased solubility and stability under physiological conditions.

BACKGROUND OF THE INVENTION

Since the development of cisplatin, great effort has been put on platinum complexes to study their anti-cancerous properties and to develop anti-cancer agents based on these complexes. Cisplatin and its derivatives are used as chemotherapeutic agents against various forms of cancer including testicular, bladder, head and neck, ovarian, breast, lung, prostate, and refractory non-Hodgkin’s lymphomas. However, platinum-based anti-cancer drugs possess several drawbacks. These include toxic side effects and the emergence of drug resistance during clinical applications. These have prompted the development of alternative metal-based anticancer drugs, e.g., gold, iridium and ruthenium complexes. In recent years, iridium complexes have been reported for biological studies due to their strong luminescent properties (Zhong, et al., Chemical Science 2015, 6, 5400-5408; Yang, et al., Chemical Science, 2016, 7, 3123-3136) and anti-cancer properties (Song, et al., J. Med. Chem. 2013, 56, 6531-6535; Liu, et al., J. Med. Chem. 2011, 54, 3011–3026) . U.S. patent application publication No. 2005/0214576 by Lamansky, et al., U.S. patent No. 7,553,560 to Lamanksy, et al., and WO 2005/118606 describe organometallic compounds, including iridium (III) disphosphine complexes as organic light emitting substances. Accordingly, there is still a need to develop metal complexes or compounds with improved properties, such as with anti-cancer properties, for biomedical applications.

It is an object of the present invention to provide metal complexes or compounds which inhibit the growth of cancer cells, display luminescent properties, or a combination thereof.

It is also an object of the present invention to provide compounds with improved stability and solubility under physiological conditions.

SUMMARY OF THE INVENTION

Diphosphino-organometallic complexes or compounds, methods of making and of use thereof, are provided. The compounds can have the general formula:

wherein

r is an integer between 0 and 5, inclusive, preferably 2;

q is an integer between 1 and 6, inclusive, preferably 1;

M is a transition metal, preferably iridium;

the oxidation state of M is between +1 and +7, inclusive, preferably +3;

R ₁’, R ₂’, R ₅’, and R ₆’are preferably, independently, unsubstituted aryl, substituted aryl, unsubstituted C ₃-C ₆ cycloalkyl, substituted C ₃-C ₆ cycloalkyl;

R ₇’and R ₈’are preferably, independently, substituted aryl, unsubstituted aryl, substituted heteroaryl, unsubstituted heteroaryl, substituted polyaryl, unsubstituted polyaryl, substituted polyheteroaryl, unsubstituted polyheteroaryl;

A’preferably is a single bond; and

preferably R ₃’and R ₄’together form R ₉’, wherein, R ₉’is preferably unsubstituted C ₁ alkylene, unsubstituted C ₂ alkylene, unsubstituted C ₃ alkylene, unsubstituted C ₄ alkylene, or unsubstituted C ₅ alkylene.

The compounds are stable towards hydrolysis and in reducing conditions, such as in physiologically reducing conditions. For instance, the complexes are tolerant to attack by excess glutathione in cellular media. The compounds inhibit growth of or display cytotoxicity against a panel of cancer cell lines. Optionally, the compounds include moieties that impart luminescent properties to the compounds in physiological conditions. For instance, the compounds can be luminescent in cellular environments.

Pharmaceutical compositions including an effective amount of one or more of the compounds are also provided. The compounds and compositions thereof can be administered to a subject in need thereof to treat a host of diseases and disorders including, but not limited to, proliferative disorders such as cancer.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a graph of absorption/emission spectra (in argon) of complex 1a·Cl and 8·Cl in degassed CH ₃CN upon excitation at λ _ex = 410 nm (1a·Cl) and 360 nm (8·Cl) .

Figure 2 is a graph of wavelength against absorbance of complex 8. Cl in MeOH at zero and 24 hours.

Figures 3A-3E are NMR spectra of iridium (III) complexes upon addition of glutathione. Figures 3A, 3B, 3C, 3D, and 3E show the stabilities of 2. PF ₆, 3. PF ₆, 5. PF ₆, 7. PF ₆, and 8. Cl, respectively.

Figure 4 is a graph of time course of uptake of 1a·Cl (1 μM) and 8·Cl (1 μM) by HeLa cancer cells. The cellular iridium content was determined by inductively coupled plasma mass spectrometry (ICP-MS) .

Figures 5A-5F are graphs of tumor size (5A, 5C, 5E) or average body weight (5B, 5D, 5F) vs. time after administration of complex 8. Cl. Figure 5A, growth curves of tumors in different intraperitoneal treatment groups. **, p ≤0.05 or *, p ≤ 0.1 compared to solvent control. Data are shown as mean ± SEM. Solvent control, n = 5 (solid line) ; Complex 8·Cl (3 mg /kg) , n = 5 (dashed line) . Figure 5B, average body weight vs. number of days after treatment of mice in different intraperitoneal treatment groups. Data are shown as mean ± SEM. Figure 5C, growth curves of tumors in different intratumoral treatment groups. Figure 5D, average body weight vs. number of days after treatment of mice in different intratumoral treatment groups. Figure 5E, growth curves of tumors in different intravenous treatment groups. Figure 5F, average body weight vs. number of days after treatment of mice in different intravenous treatment groups.

DETAILED DESCRIPTION OF THE INVENTION

I. DEFINITIONS

It is to be understood that the disclosed compounds, compositions, and methods are not limited to specific synthetic methods, specific analytical techniques, or to particular reagents unless otherwise specified, and, as such, may vary. It is also to be understood that the terminology used herein is for the purpose of describing particular forms and embodiments only and is not intended to be limiting.

The terms “diphosphine” and “diphosphino” are used interchangeably, and refer to a ligand or metallic complex that contains two phosphorus atoms. Preferably, the phosphorus atoms can chelate, as in the case of the ligand, or are chelating a central metal atom in the case of a metallic complex.

“Substituted, ” as used herein, refers to all permissible substituents of the compounds or functional groups described herein. In the broadest sense, the permissible substituents include acyclic and cyclic, branched and unbranched, carbocyclic and heterocyclic, aromatic and nonaromatic substituents of organic compounds. Illustrative substituents include, but are not limited to, halogens, hydroxyl groups, or any other organic groupings containing any number of carbon atoms, preferably 1-14 carbon atoms, and optionally include one or more heteroatoms such as oxygen, sulfur, or nitrogen grouping in linear, branched, or cyclic structural formats. Representative substituents include alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, phenyl, substituted phenyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, halo, hydroxyl, alkoxy, substituted alkoxy, phenoxy, substituted phenoxy, aroxy, substituted aroxy, alkylthio, substituted alkylthio, phenylthio, substituted phenylthio, arylthio, substituted arylthio, cyano, isocyano, substituted isocyano, carbonyl, substituted carbonyl, carboxyl, substituted carboxyl, amino, substituted amino, amido, substituted amido, sulfonyl, substituted sulfonyl, sulfonic acid, phosphoryl, substituted phosphoryl, phosphonyl, substituted phosphonyl, polyaryl, substituted polyaryl, C ₃-C ₂₀ cyclic, substituted C ₃-C ₂₀ cyclic, heterocyclic, substituted heterocyclic, amino acid, poly (lactic-co-glycolic acid) , peptide, and polypeptide groups. Such alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, phenyl, substituted phenyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, halo, hydroxyl, alkoxy, substituted alkoxy, phenoxy, substituted phenoxy, aroxy, substituted aroxy, alkylthio, substituted alkylthio, phenylthio, substituted phenylthio, arylthio, substituted arylthio, cyano, isocyano, substituted isocyano, carbonyl, substituted carbonyl, carboxyl, substituted carboxyl, amino, substituted amino, amido, substituted amido, sulfonyl, substituted sulfonyl, sulfonic acid, phosphoryl, substituted phosphoryl, phosphonyl, substituted phosphonyl, polyaryl, substituted polyaryl, C ₃-C ₂₀ cyclic, substituted C ₃-C ₂₀ cyclic, heterocyclic, substituted heterocyclic, amino acid, poly (lactic-co-glycolic acid) , peptide, and polypeptide groups can be further substituted.

Heteroatoms such as nitrogen may have hydrogen substituents and/or any permissible substituents of organic compounds described herein which satisfy the valences of the heteroatoms. It is understood that “substitution” or “substituted” includes the implicit proviso that such substitution is in accordance with permitted valence of the substituted atom and the substituent, and that the substitution results in a stable compound, i.e. a compound that does not spontaneously undergo transformation such as by rearrangement, cyclization, elimination, etc.

“Alkyl, ” as used herein, refers to the radical of saturated aliphatic groups, including straight-chain alkyl groups, branched-chain alkyl, cycloalkyl (alicyclic) , alkyl substituted cycloalkyl groups, and cycloalkyl substituted alkyl. In preferred forms, a straight chain or branched chain alkyl has 30 or fewer carbon atoms in its backbone (e.g., C ₁-C ₃₀ for straight chains, C ₃-C ₃₀ for branched chains) , preferably 20 or fewer, more preferably 15 or fewer, most preferably 10 or fewer. Alkyl includes methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, pentyl, hexyl, heptyl, octyl, decyl, tetradecyl, hexadecyl, eicosyl, tetracosyl and the like.

Likewise, preferred cycloalkyls have from 3-10 carbon atoms in their ring structure, and more preferably have 5, 6 or 7 carbons in the ring structure. The term "alkyl" (or "lower alkyl" ) as used throughout the specification, examples, and claims is intended to include both "unsubstituted alkyls" and "substituted alkyls, ” the latter of which refers to alkyl moieties having one or more substituents replacing a hydrogen on one or more carbons of the hydrocarbon backbone. Such substituents include, but are not limited to, halogen, hydroxyl, carbonyl (such as a carboxyl, alkoxycarbonyl, formyl, or an acyl) , thiocarbonyl (such as a thioester, a thioacetate, or a thioformate) , alkoxyl, phosphoryl, phosphate, phosphonate, a phosphinate, amino, amido, amidine, imine, cyano, nitro, azido, sulfhydryl, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, aralkyl, or an aromatic or heteroaromatic moiety.

Unless the number of carbons is otherwise specified, "lower alkyl" as used herein means an alkyl group, as defined above, but having from one to ten carbons, more preferably from one to six carbon atoms in its backbone structure. Likewise, "lower alkenyl" and "lower alkynyl" have similar chain lengths. Throughout the application, preferred alkyl groups are lower alkyls. In preferred forms, a substituent designated herein as alkyl is a lower alkyl.

“Alkyl” includes one or more substitutions at one or more carbon atoms of the hydrocarbon radical as well as heteroalkyls. Suitable substituents include, but are not limited to, halogens, such as fluorine, chlorine, bromine, or iodine; hydroxyl; -NRR’, wherein R and R’are independently hydrogen, alkyl, or aryl, and wherein the nitrogen atom is optionally quaternized; -SR, wherein R is hydrogen, alkyl, or aryl; -CN; -NO ₂; -COOH; carboxylate; -COR, -COOR, or -CON (R) ₂, wherein R is hydrogen, alkyl, or aryl; azide, aralkyl, alkoxyl, imino, phosphonate, phosphinate, silyl, ether, sulfonyl, sulfonamido, heterocyclyl, aromatic or heteroaromatic moieties, haloalkyl (such as -CF ₃, -CH ₂-CF ₃, -CCl ₃) ; -CN; -NCOCOCH ₂CH ₂; -NCOCOCHCH; -NCS; and combinations thereof.

It will be understood by those skilled in the art that the moieties substituted on the hydrocarbon chain can themselves be substituted, if appropriate. For instance, the substituents of a substituted alkyl may include halogen, hydroxy, nitro, thiols, amino, azido, imino, amido, phosphoryl (including phosphonate and phosphinate) , sulfonyl (including sulfate, sulfonamido, sulfamoyl and sulfonate) , and silyl groups, as well as ethers, alkylthios, carbonyls (including ketones, aldehydes, carboxylates, and esters) , haloalkyls, -CN and the like. Cycloalkyls can be substituted in the same manner.

“Heteroalkyl, ” as used herein, refers to straight or branched chain, or cyclic carbon-containing radicals, or combinations thereof, containing at least one heteroatom. Suitable heteroatoms include, but are not limited to, O, N, Si, P and S, wherein the nitrogen, phosphorous and sulfur atoms are optionally oxidized, and the nitrogen heteroatom is optionally quaternized.

The terms “alkoxyl” or “alkoxy, ” “aroxy” or “aryloxy, ” generally describe compounds represented by the formula -OR ^v, wherein R ^v includes, but is not limited to, substituted or unsubstituted alkyl, alkenyl, alkynyl, cycloalkyl, heterocyclyl, cycloalkenyl, heterocycloalkenyl, aryl, heteroaryl, arylalkyl, heteroalkyls, alkylaryl, alkylheteroaryl.

The terms "alkoxyl" or "alkoxy" as used herein refer to an alkyl group, as defined above, having an oxygen radical attached thereto. Representative alkoxyl groups include methoxy, ethoxy, propyloxy, tert-butoxy and the like. An “ether” is two hydrocarbons covalently linked by an oxygen. Accordingly, the substituent of an alkyl that renders that alkyl an ether is or resembles an alkoxyl, such as can be represented by one of -O-alkyl, -O-alkenyl, and -O-alkynyl. The term alkoxy also includes cycloalkyl, heterocyclyl, cycloalkenyl, heterocycloalkenyl, and arylalkyl having an oxygen radical attached to at least one of the carbon atoms, as valency permits. A “lower alkoxy” group is an alkoxy group containing from one to six carbon atoms.

The term “substituted alkoxy” refers to an alkoxy group having one or more substituents replacing one or more hydrogen atoms on one or more carbons of the alkoxy backbone. Such substituents include, but are not limited to, halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, carbonyl (such as a carboxyl, alkoxycarbonyl, formyl, or an acyl) , silyl, ether, ester, thiocarbonyl (such as a thioester, a thioacetate, or a thioformate) , alkoxyl, phosphoryl, phosphate, phosphonate, phosphinate, amino (or quarternized amino) , amido, amidine, imine, cyano, nitro, azido, sulfhydryl, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, alkylaryl, haloalkyl, -CN, aryl, heteroaryl, and combinations thereof.

The term “alkenyl” as used herein is a hydrocarbon group of from 2 to 24 carbon atoms and structural formula containing at least one carbon-carbon double bond. Asymmetric structures such as (AB) C=C (CD) are intended to include both the E and Z isomers. This may be presumed in structural formulae herein wherein an asymmetric alkene is present, or it may be explicitly indicated by the bond symbol C.

The term “alkynyl group” as used herein is a hydrocarbon group of 2 to 24 carbon atoms and a structural formula containing at least one carbon-carbon triple bond.

The term “aryl” as used herein is any C ₅-C ₂₆ carbon-based aromatic group, fused aromatic, fused heterocyclic, or biaromatic ring systems. Broadly defined, “aryl, ” as used herein, includes 5-, 6-, 7-, 8-, 9-, 10-, 14-, 18-, and 24-membered single-ring aromatic groups, including, but not limited to, benzene, naphthalene, anthracene, phenanthrene, chrysene, pyrene, corannulene, coronene, etc. “Aryl” further encompasses polycyclic ring systems having two or more cyclic rings in which two or more carbons are common to two adjoining rings (i.e., “fused rings” ) wherein at least one of the rings is aromatic, e.g., the other cyclic ring or rings can be cycloalkyls, cycloalkenyls, cycloalkynyls, aryls and/or heterocycles. The aryl group can be substituted with one or more groups including, but not limited to, alkyl, alkynyl, alkenyl, aryl, halide, nitro, amino, ester, ketone, aldehyde, hydroxy, carboxylic acid, or alkoxy.

The term “substituted aryl” refers to an aryl group, wherein one or more hydrogen atoms on one or more aromatic rings are substituted with one or more substituents including, but not limited to, halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, alkoxy, carbonyl (such as a ketone, aldehyde, carboxyl, alkoxycarbonyl, formyl, or an acyl) , silyl, ether, ester, thiocarbonyl (such as a thioester, a thioacetate, or a thioformate) , alkoxyl, phosphoryl, phosphate, phosphonate, phosphinate, amino (or quarternized amino) , amido, amidine, imine, cyano, nitro, azido, sulfhydryl, imino, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, alkylaryl, haloalkyl (such as CF ₃, -CH ₂-CF ₃, -CCl ₃) , -CN, aryl, heteroaryl, and combinations thereof.

“Heterocycle, ” “heterocyclic” and “heterocyclyl” are used interchangeably, and refer to a cyclic radical attached via a ring carbon or nitrogen atom of a monocyclic or bicyclic ring containing 3-10 ring atoms, and preferably from 5-6 ring atoms, consisting of carbon and one to four heteroatoms each selected from the group consisting of non-peroxide oxygen, sulfur, and N (Y) wherein Y is absent or is H, O, C ₁-C ₁₀ alkyl, phenyl or benzyl, and optionally containing 1-3 double bonds and optionally substituted with one or more substituents. Heterocyclyl are distinguished from heteroaryl by definition. Examples of heterocycles include, but are not limited to piperazinyl, piperidinyl, piperidonyl, 4-piperidonyl, dihydrofuro [2, 3-b] tetrahydrofuran, morpholinyl, piperazinyl, piperidinyl, piperidonyl, 4-piperidonyl, piperonyl, pyranyl, 2H-pyrrolyl, 4H-quinolizinyl, quinuclidinyl, tetrahydrofuranyl, 6H-1, 2, 5-thiadiazinyl. Heterocyclic groups can optionally be substituted with one or more substituents as defined above for alkyl and aryl.

The term “heteroaryl” refers to C ₅-C ₂₆-membered aromatic, fused aromatic, biaromatic ring systems, or combinations thereof, in which one or more carbon atoms on one or more aromatic ring structures have been substituted with a heteroatom. Suitable heteroatoms include, but are not limited to, oxygen, sulfur, and nitrogen. Broadly defined, “heteroaryl, ” as used herein, includes 5-, 6-, 7-, 8-, 9-, 10-, 14-, 18-, and 24-membered single-ring aromatic groups that may include from one to four heteroatoms, for example, pyrrole, furan, thiophene, imidazole, oxazole, thiazole, triazole, tetrazole, pyrazole, pyridine, pyrazine, pyridazine and pyrimidine, and the like. The heteroaryl group may also be referred to as “aryl heterocycles” or “heteroaromatics” . “Heteroaryl” further encompasses polycyclic ring systems having two or more rings in which two or more carbons are common to two adjoining rings (i.e., “fused rings” ) wherein at least one of the rings is heteroaromatic, e.g., the other cyclic ring or rings can be cycloalkyls, cycloalkenyls, cycloalkynyls, aryls, heterocycles, or combinations thereof. Examples of heteroaryl rings include, but are not limited to, benzimidazolyl, benzofuranyl, benzothiofuranyl, benzothiophenyl, benzoxazolyl, benzoxazolinyl, benzthiazolyl, benztriazolyl, benztetrazolyl, benzisoxazolyl, benzisothiazolyl, benzimidazolinyl, carbazolyl, 4aH-carbazolyl, carbolinyl, chromanyl, chromenyl, cinnolinyl, decahydroquinolinyl, 2H, 6H-1, 5, 2-dithiazinyl, furanyl, furazanyl, imidazolidinyl, imidazolinyl, imidazolyl, 1H-indazolyl, indolenyl, indolinyl, indolizinyl, indolyl, 3H-indolyl, isatinoyl, isobenzofuranyl, isochromanyl, isoindazolyl, isoindolinyl, isoindolyl, isoquinolinyl, isothiazolyl, isoxazolyl, methylenedioxyphenyl, naphthyridinyl, octahydroisoquinolinyl, 1, 2, 3-oxadiazolyl, 1, 2, 4-oxadiazolyl, 1, 2, 5-oxadiazolyl, 1, 3, 4-oxadiazolyl, oxazolidinyl, oxazolyl, oxindolyl, pyrimidinyl, phenanthridinyl, phenanthrolinyl, phenazinyl, phenothiazinyl, phenoxathinyl, phenoxazinyl, phthalazinyl, pteridinyl, purinyl, pyrazinyl, pyrazolidinyl, pyrazolinyl, pyrazolyl, pyridazinyl, pyridooxazole, pyridoimidazole, pyridothiazole, pyridinyl, pyridyl, pyrimidinyl, pyrrolidinyl, pyrrolinyl, pyrrolyl, quinazolinyl, quinolinyl, quinoxalinyl, tetrahydroisoquinolinyl, tetrahydroquinolinyl, tetrazolyl, 1, 2, 3-thiadiazolyl, 1, 2, 4-thiadiazolyl, 1, 2, 5-thiadiazolyl, 1, 3, 4-thiadiazolyl, thianthrenyl, thiazolyl, thienyl, thienothiazolyl, thienooxazolyl, thienoimidazolyl, thiophenyl and xanthenyl. One or more of the rings can be substituted as defined below for “substituted heteroaryl” .

The term “substituted heteroaryl” refers to a heteroaryl group in which one or more hydrogen atoms on one or more heteroaromatic rings are substituted with one or more substituents including, but not limited to, halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, alkoxy, carbonyl (such as a ketone, aldehyde, carboxyl, alkoxycarbonyl, formyl, or an acyl) , silyl, ether, ester, thiocarbonyl (such as a thioester, a thioacetate, or a thioformate) , alkoxyl, phosphoryl, phosphate, phosphonate, phosphinate, amino (or quarternized amino) , amido, amidine, imine, cyano, nitro, azido, sulfhydryl, imino, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, alkylaryl, haloalkyl (such as CF ₃, -CH ₂-CF ₃, -CCl ₃) , -CN, aryl, heteroaryl, and combinations thereof.

The term “substituted alkenyl” refers to alkenyl moieties having one or more substituents replacing one or more hydrogen atoms on one or more carbons of the hydrocarbon backbone. Such substituents include, but are not limited to, halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, carbonyl (such as a carboxyl, alkoxycarbonyl, formyl, or an acyl) , silyl, ether, ester, thiocarbonyl (such as a thioester, a thioacetate, or a thioformate) , alkoxyl, phosphoryl, phosphate, phosphonate, phosphinate, amino (or quarternized amino) , amido, amidine, imine, cyano, nitro, azido, sulfhydryl, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, alkylaryl, haloalkyl, -CN, aryl, heteroaryl, and combinations thereof.

The term “substituted alkynyl” refers to alkynyl moieties having one or more substituents replacing one or more hydrogen atoms on one or more carbons of the hydrocarbon backbone. Such substituents include, but are not limited to, halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, carbonyl (such as a carboxyl, alkoxycarbonyl, formyl, or an acyl) , silyl, ether, ester, thiocarbonyl (such as a thioester, a thioacetate, or a thioformate) , alkoxyl, phosphoryl, phosphate, phosphonate, phosphinate, amino (or quarternized amino) , amido, amidine, imine, cyano, nitro, azido, sulfhydryl, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, alkylaryl, haloalkyl, -CN, aryl, heteroaryl, and combinations thereof.

The term “cycloalkyl” as used herein is a non-aromatic carbon-based ring composed of at least three carbon atoms. Examples of cycloalkyl groups include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, etc. The term “heterocycloalkyl group” is a cycloalkyl group as defined above where at least one of the carbon atoms of the ring is substituted with a heteroatom such as, but not limited to, nitrogen, oxygen, sulphur, or phosphorus.

The term “aralkyl” as used herein is an aryl group having an alkyl, alkynyl, or alkenyl group as defined above attached to the aromatic group. An example of an aralkyl group is a benzyl group.

The term “hydroxyalkyl group” as used herein is an alkyl, alkenyl, alkynyl, aryl, aralkyl, cycloalkyl, halogenated alkyl, or heterocycloalkyl group described above that has at least one hydrogen atom substituted with a hydroxyl group.

The term “alkoxyalkyl group” is defined as an alkyl, alkenyl, alkynyl, aryl, aralkyl, cycloalkyl, halogenated alkyl, or heterocycloalkyl group described above that has at least one hydrogen atom substituted with an alkoxy group described above.

“Carbonyl, ” as used herein, is art-recognized and includes such moieties as can be represented by the general formula:

wherein X is a bond, or represents an oxygen or a sulfur, and R represents a hydrogen, a substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted alkylaryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl, - (CH ₂) _m-R”, or a pharmaceutical acceptable salt, R’represents a hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted alkylaryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl or - (CH ₂) _m-R”; R”represents a hydroxy group, substituted or unsubstituted carbonyl group, an aryl, a cycloalkyl ring, a cycloalkenyl ring, a heterocycle, or a polycycle; and m is zero or an integer ranging from 1 to 8. Where X is oxygen and R is defines as above, the moiety is also referred to as a carboxyl group. When X is oxygen and R is hydrogen, the formula represents a ‘carboxylic acid’ . Where X is oxygen and R’is hydrogen, the formula represents a ‘formate’ . Where X is oxygen and R or R’is not hydrogen, the formula represents an "ester" . In general, where the oxygen atom of the above formula is replaced by a sulfur atom, the formula represents a ‘thiocarbonyl’ group. Where X is sulfur and R or R’is not hydrogen, the formula represents a ‘thioester. ’ Where X is sulfur and R is hydrogen, the formula represents a ‘thiocarboxylic acid. ’ Where X is sulfur and R’is hydrogen, the formula represents a ‘thioformate. ’ Where X is a bond and R is not hydrogen, the above formula represents a ‘ketone. ’ Where X is a bond and R is hydrogen, the above formula represents an ‘aldehyde. ’

The term “substituted carbonyl” refers to a carbonyl, as defined above, wherein one or more hydrogen atoms in R, R’or a group to which the moiety

is attached, are independently substituted. Such substituents include, but are not limited to, halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, carbonyl (such as a carboxyl, alkoxycarbonyl, formyl, or an acyl) , silyl, ether, ester, thiocarbonyl (such as a thioester, a thioacetate, or a thioformate) , alkoxyl, phosphoryl, phosphate, phosphonate, phosphinate, amino (or quarternized amino) , amido, amidine, imine, cyano, nitro, azido, sulfhydryl, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, alkylaryl, haloalkyl, -CN, aryl, heteroaryl, and combinations thereof.

The term “carboxyl” is as defined above for the formula

and is defined more specifically by the formula -R ^ivCOOH, wherein R ^iv is an alkyl, alkenyl, alkynyl, cycloalkyl, heterocyclyl, alkylaryl, arylalkyl, aryl, or heteroaryl. In preferred forms, a straight chain or branched chain alkyl, alkenyl, and alkynyl have 30 or fewer carbon atoms in its backbone (e.g., C ₁-C ₃₀ for straight chain alkyl, C ₃-C ₃₀ for branched chain alkyl, C ₂-C ₃₀ for straight chain alkenyl and alkynyl, C ₃-C ₃₀ for branched chain alkenyl and alkynyl) , preferably 20 or fewer, more preferably 15 or fewer, most preferably 10 or fewer. Likewise, preferred cycloalkyls, heterocyclyls, aryls and heteroaryls have from 3-10 carbon atoms in their ring structure, and more preferably have 5, 6 or 7 carbons in the ring structure.

The term “substituted carboxyl” refers to a carboxyl, as defined above, wherein one or more hydrogen atoms in R ^iv are substituted. Such substituents include, but are not limited to, halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, carbonyl (such as a carboxyl, alkoxycarbonyl, formyl, or an acyl) , silyl, ether, ester, thiocarbonyl (such as a thioester, a thioacetate, or a thioformate) , alkoxyl, phosphoryl, phosphate, phosphonate, phosphinate, amino (or quarternized amino) , amido, amidine, imine, cyano, nitro, azido, sulfhydryl, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, alkylaryl, haloalkyl, -CN, aryl, heteroaryl, and combinations thereof.

The term “phenoxy” is art recognized, and refers to a compound of the formula -OR ^v wherein R ^v is (i.e., -O-C ₆H ₅) . One of skill in the art recognizes that a phenoxy is a species of the aroxy genus.

The term “substituted phenoxy” refers to a phenoxy group, as defined above, having one or more substituents replacing one or more hydrogen atoms on one or more carbons of the phenyl ring. Such substituents include, but are not limited to, halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, carbonyl (such as a carboxyl, alkoxycarbonyl, formyl, or an acyl) , silyl, ether, ester, thiocarbonyl (such as a thioester, a thioacetate, or a thioformate) , alkoxyl, phosphoryl, phosphate, phosphonate, phosphinate, amino (or quarternized amino) , amido, amidine, imine, cyano, nitro, azido, sulfhydryl, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, alkylaryl, haloalkyl, -CN, aryl, heteroaryl, and combinations thereof.

The terms “aroxy” and “aryloxy, ” as used interchangeably herein, are represented by -O-aryl or -O-heteroaryl, wherein aryl and heteroaryl are as defined herein.

The terms “substituted aroxy” and “substituted aryloxy, ” as used interchangeably herein, represent -O-aryl or -O-heteroaryl, having one or more substituents replacing one or more hydrogen atoms on one or more ring atoms of the aryl and heteroaryl, as defined herein. Such substituents include, but are not limited to, halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, carbonyl (such as a carboxyl, alkoxycarbonyl, formyl, or an acyl) , silyl, ether, ester, thiocarbonyl (such as a thioester, a thioacetate, or a thioformate) , alkoxyl, phosphoryl, phosphate, phosphonate, phosphinate, amino (or quarternized amino) , amido, amidine, imine, cyano, nitro, azido, sulfhydryl, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, alkylaryl, haloalkyl, -CN, aryl, heteroaryl, and combinations thereof.

The term "alkylthio" refers to an alkyl group, as defined above, having a sulfur radical attached thereto. The "alkylthio" moiety is represented by -S-alkyl. Representative alkylthio groups include methylthio, ethylthio, and the like. The term “alkylthio” also encompasses cycloalkyl groups having a sulfur radical attached thereto.

The term “substituted alkylthio” refers to an alkylthio group having one or more substituents replacing one or more hydrogen atoms on one or more carbon atoms of the alkylthio backbone. Such substituents include, but are not limited to, halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, carbonyl (such as a carboxyl, alkoxycarbonyl, formyl, or an acyl) , silyl, ether, ester, thiocarbonyl (such as a thioester, a thioacetate, or a thioformate) , alkoxyl, phosphoryl, phosphate, phosphonate, phosphinate, amino (or quarternized amino) , amido, amidine, imine, cyano, nitro, azido, sulfhydryl, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, alkylaryl, haloalkyl, -CN, aryl, heteroaryl, and combinations thereof.

The term “phenylthio” is art recognized, and refers to -S-C ₆H ₅, i.e., a phenyl group attached to a sulfur atom.

The term “substituted phenylthio” refers to a phenylthio group, as defined above, having one or more substituents replacing a hydrogen on one or more carbons of the phenyl ring. Such substituents include, but are not limited to, halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, carbonyl (such as a carboxyl, alkoxycarbonyl, formyl, or an acyl) , silyl, ether, ester, thiocarbonyl (such as a thioester, a thioacetate, or a thioformate) , alkoxyl, phosphoryl, phosphate, phosphonate, phosphinate, amino (or quarternized amino) , amido, amidine, imine, cyano, nitro, azido, sulfhydryl, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, alkylaryl, haloalkyl, -CN, aryl, heteroaryl, and combinations thereof.

“Arylthio” refers to -S-aryl or -S-heteroaryl groups, wherein aryl and heteroaryl as defined herein.

The term “substituted arylthio” represents -S-aryl or -S-heteroaryl, having one or more substituents replacing a hydrogen atom on one or more ring atoms of the aryl and heteroaryl rings as defined herein. Such substituents include, but are not limited to, halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, carbonyl (such as a carboxyl, alkoxycarbonyl, formyl, or an acyl) , silyl, ether, ester, thiocarbonyl (such as a thioester, a thioacetate, or a thioformate) , alkoxyl, phosphoryl, phosphate, phosphonate, phosphinate, amino (or quarternized amino) , amido, amidine, imine, cyano, nitro, azido, sulfhydryl, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, alkylaryl, haloalkyl, -CN, aryl, heteroaryl, and combinations thereof.

The terms “amide” or “amido” are used interchangeably, refer to both “unsubstituted amido” and “substituted amido” and are represented by the general formula:

wherein, E is absent, or E is substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aralkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted heterocyclyl, wherein independently of E, R and R’each independently represent a hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted carbonyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted alkylaryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl, - (CH ₂) _m-R”’, or R and R’taken together with the N atom to which they are attached complete a heterocycle having from 3 to 14 atoms in the ring structure; R”’represents a hydroxy group, substituted or unsubstituted carbonyl group, an aryl, a cycloalkyl ring, a cycloalkenyl ring, a heterocycle, or a polycycle; and m is zero or an integer ranging from 1 to 8. In preferred forms, only one of R and R’can be a carbonyl, e.g., R and R’together with the nitrogen do not form an imide. In preferred forms, R and R’each independently represent a hydrogen atom, substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, or - (CH ₂) _m-R”’. When E is oxygen, a carbamate is formed. The carbamate cannot be attached to another chemical species, such as to form an oxygen-oxygen bond, or other unstable bonds, as understood by one of ordinary skill in the art.

The term “sulfonyl” is represented by the formula

wherein E is absent, or E is alkyl, alkenyl, alkynyl, aralkyl, alkylaryl, cycloalkyl, aryl, heteroaryl, heterocyclyl, wherein independently of E, R represents a hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted amine, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted alkylaryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl, - (CH ₂) _m-R”’, or E and R taken together with the S atom to which they are attached complete a heterocycle having from 3 to 14 atoms in the ring structure; R”’represents a hydroxy group, substituted or unsubstituted carbonyl group, an aryl, a cycloalkyl ring, a cycloalkenyl ring, a heterocycle, or a polycycle; and m is zero or an integer ranging from 1 to 8. In preferred forms, only one of E and R can be substituted or unsubstituted amine, to form a “sulfonamide” or “sulfonamido. ” The substituted or unsubstituted amine is as defined above.

The term “substituted sulfonyl” represents a sulfonyl in which E, R, or both, are independently substituted. Such substituents include, but are not limited to, halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, carbonyl (such as a carboxyl, alkoxycarbonyl, formyl, or an acyl) , silyl, ether, ester, thiocarbonyl (such as a thioester, a thioacetate, or a thioformate) , alkoxyl, phosphoryl, phosphate, phosphonate, phosphinate, amino (or quarternized amino) , amido, amidine, imine, cyano, nitro, azido, sulfhydryl, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, alkylaryl, haloalkyl, -CN, aryl, heteroaryl, and combinations thereof.

The term “sulfonic acid” refers to a sulfonyl, as defined above, wherein R is hydroxyl, and E is absent, or E is substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted alkylaryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl.

The term “sulfate” refers to a sulfonyl, as defined above, wherein E is absent, oxygen, alkoxy, aroxy, substituted alkoxy or substituted aroxy, as defined above, and R is independently hydroxyl, alkoxy, aroxy, substituted alkoxy or substituted aroxy, as defined above. When E is oxygen, the sulfate cannot be attached to another chemical species, such as to form an oxygen-oxygen bond, or other unstable bonds, as understood by one of ordinary skill in the art.

The term “sulfonate” refers to a sulfonyl, as defined above, wherein E is oxygen, alkoxy, aroxy, substituted alkoxy or substituted aroxy, as defined above, and R is independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted amine, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted alkylaryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl, - (CH ₂) _m-R”’, R”’represents a hydroxy group, substituted or unsubstituted carbonyl group, an aryl, a cycloalkyl ring, a cycloalkenyl ring, a heterocycle, or a polycycle; and m is zero or an integer ranging from 1 to 8. When E is oxygen, sulfonate cannot be attached to another chemical species, such as to form an oxygen-oxygen bond, or other unstable bonds, as understood by one of ordinary skill in the art.

The term “sulfamoyl” refers to a sulfonamide or sulfonamide represented by the formula

wherein E is absent, or E is substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aralkyl, substituted or unsubstituted alkylaryl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted heterocyclyl, wherein independently of E, R and R’each independently represent a hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted carbonyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted alkylaryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl, - (CH ₂) _m-R”’, or R and R’taken together with the N atom to which they are attached complete a heterocycle having from 3 to 14 atoms in the ring structure; R”’represents a hydroxy group, substituted or unsubstituted carbonyl group, an aryl, a cycloalkyl ring, a cycloalkenyl ring, a heterocycle, or a polycycle; and m is zero or an integer ranging from 1 to 8. In preferred forms, only one of R and R’can be a carbonyl, e.g., R and R’together with the nitrogen do not form an imide.

The term “phosphonyl” is represented by the formula

wherein E is absent, or E is substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aralkyl, substituted or unsubstituted alkylaryl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted heterocyclyl, , wherein, independently of E, R ^vi and R ^vii are independently hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted carbonyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted heterocyclyl, substituted or unsubstituted alkylaryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl, - (CH ₂) _m-R”’, or R and R’taken together with the P atom to which they are attached complete a heterocycle having from 3 to 14 atoms in the ring structure; R”’represents a hydroxy group, substituted or unsubstituted carbonyl group, an aryl, a cycloalkyl ring, a cycloalkenyl ring, a heterocycle, or a polycycle; and m is zero or an integer ranging from 1 to 8.

The term “substituted phosphonyl” represents a phosphonyl in which E, R ^vi and R ^vii are independently substituted. Such substituents include, but are not limited to, halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, carbonyl (such as a carboxyl, alkoxycarbonyl, formyl, or an acyl) , silyl, ether, ester, thiocarbonyl (such as a thioester, a thioacetate, or a thioformate) , alkoxyl, phosphoryl, phosphate, phosphonate, phosphinate, amino (or quarternized amino) , amido, amidine, imine, cyano, nitro, azido, sulfhydryl, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, alkylaryl, haloalkyl, -CN, aryl, heteroaryl, and combinations thereof.

The term “phosphoryl” defines a phosphonyl in which E is absent, oxygen, alkoxy, aroxy, substituted alkoxy or substituted aroxy, as defined above, and independently of E, R ^vi and R ^vii are independently hydroxyl, alkoxy, aroxy, substituted alkoxy or substituted aroxy, as defined above. When E is oxygen, the phosphoryl cannot be attached to another chemical species, such as to form an oxygen-oxygen bond, or other unstable bonds, as understood by one of ordinary skill in the art. When E, R ^vi and R ^vii are substituted, the substituents include, but are not limited to, halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, carbonyl (such as a carboxyl, alkoxycarbonyl, formyl, or an acyl) , silyl, ether, ester, thiocarbonyl (such as a thioester, a thioacetate, or a thioformate) , alkoxyl, phosphoryl, phosphate, phosphonate, phosphinate, amino (or quarternized amino) , amido, amidine, imine, cyano, nitro, azido, sulfhydryl, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, alkylaryl, haloalkyl, -CN, aryl, heteroaryl, and combinations thereof.

The term “polyaryl” refers to a chemical moiety that includes two or more aryls, heteroaryls, and combinations thereof. The aryls, heteroaryls, and combinations thereof, are fused, or linked via a single bond, ether, ester, carbonyl, amide, sulfonyl, sulfonamide, alkyl, azo, and combinations thereof. When two or more heteroaryls are involved, the chemical moiety can be referred to as a “polyheteroaryl. ”

The term “substituted polyaryl” refers to a polyaryl in which one or more of the aryls, heteroaryls are substituted, with one or more substituents including, but not limited to, halogen, azide, alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, carbonyl (such as a carboxyl, alkoxycarbonyl, formyl, or an acyl) , silyl, ether, ester, thiocarbonyl (such as a thioester, a thioacetate, or a thioformate) , alkoxyl, phosphoryl, phosphate, phosphonate, phosphinate, amino (or quarternized amino) , amido, amidine, imine, cyano, nitro, azido, sulfhydryl, alkylthio, sulfate, sulfonate, sulfamoyl, sulfonamido, sulfonyl, heterocyclyl, alkylaryl, haloalkyl, -CN, aryl, heteroaryl, and combinations thereof. When two or more heteroaryls are involved, the chemical moiety can be referred to as a “substituted polyheteroaryl. ”

The term “C ₃-C ₂₀ cyclic” refers to a substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, substituted or unsubstituted cycloalkynyl, substituted or unsubstituted heterocyclyl that have from three to 20 carbon atoms, as geometric constraints permit. The cyclic structures are formed from single or fused ring systems. The substituted cycloalkyls, cycloalkenyls, cycloalkynyls and heterocyclyls are substituted as defined above for the alkyls, alkenyls, alkynyls and heterocyclyls, respectively.

The term “ether” as used herein is represented by the formula AOA ¹, where A and A ¹ can be, independently, an alkyl, halogenated alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, cycloalkenyl, heterocycloalkyl, or heterocycloalkenyl group described above.

The term “urethane” as used herein is represented by the formula -OC (O) NRR’, where R and R’can be, independently, hydrogen, an alkyl, alkenyl, alkynyl, aryl, aralkyl, cycloalkyl, halogenated alkyl, or heterocycloalkyl group described above.

The term “silyl group” as used herein is represented by the formula -SiRR’R”, where R, R’, and R”can be, independently, hydrogen, an alkyl, alkenyl, alkynyl, aryl, aralkyl, cycloalkyl, halogenated alkyl, alkoxy, or heterocycloalkyl group described above.

The terms “hydroxyl” and “hydroxy” are used interchangeably and are represented by -OH.

The terms “thiol” and “sulfhydryl” are used interchangeably and are represented by –SH.

The term “oxo” refers to =O bonded to a carbon atom.

The terms “cyano” and “nitrile” are used interchangeably to refer to -CN.

The term “nitro” refers to -NO ₂.

The term “phosphate” refers to -O-PO ₃.

The term “azide” or “azido” are used interchangeably to refer to -N ₃.

The disclosed compounds and substituent groups, can, independently, possess two or more of the groups listed above. For example, if the compound or substituent group is a straight chain alkyl group, one of the hydrogen atoms of the alkyl group can be substituted with a hydroxyl group, an alkoxy group, etc. Depending upon the groups that are selected, a first group can be incorporated within second group or, alternatively, the first group can be pendant (i.e., attached) to the second group. For example, with the phrase “an alkyl group comprising an ester group, ” the ester group can be incorporated within the backbone of the alkyl group. Alternatively, the ester can be attached to the backbone of the alkyl group. The nature of the group (s) that is (are) selected will determine if the first group is embedded or attached to the second group.

The compounds and substituents can be substituted with, independently, with the substituents described above in the definition of “Substituted. ”

The terms "effective amount" and “therapeutically effective amount, ” used interchangeably, as applied to the compounds, antineoplastics, and pharmaceutical compositions described herein, mean the quantity necessary to render the desired therapeutic result. For example, an effective amount is a level effective to treat, cure, or alleviate the symptoms of a disease for which the composition and/or antineoplastic, or pharmaceutical composition, is/are being administered. Amounts effective for the particular therapeutic goal sought will depend upon a variety of factors including the disease being treated and its severity and/or stage of development/progression; the bioavailability and activity of the specific compound and/or antineoplastic, or pharmaceutical composition, used; the route or method of administration and introduction site on the subject; the rate of clearance of the specific composition and other pharmacokinetic properties; the duration of treatment; inoculation regimen; drugs used in combination or coincident with the specific composition; the age, body weight, sex, diet, physiology and general health of the subject being treated; and like factors well known to one of skill in the relevant scientific art. Some variation in dosage will necessarily occur depending upon the condition of the subject being treated, and the physician or other individual administering treatment will, in any event, determine the appropriate dosage for an individual patient.

The term “inhibit” means to reduce or decrease in activity or expression. This can be a complete inhibition or activity or expression, or a partial inhibition. Inhibition can be compared to a control or to a standard level. Inhibition can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 15 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, or 100%.

By “pharmaceutically acceptable” is meant a material that is not biologically or otherwise undesirable, i.e., the material can be administered to a subject along with the selected compound without causing any undesirable biological effects or interacting in a deleterious manner with any of the other components of the pharmaceutical composition in which it is contained.

As used herein, “treatment” or “treating” refers to arresting or inhibiting, or attempting to arrest or inhibit, the development or progression of a disease and/or causing, or attempting to cause, the reduction, suppression, regression, or remission of a disease and/or a symptom thereof. As would be understood by those skilled in the art, various clinical and scientific methodologies and assays may be used to assess the development or progression of an infection, and similarly, various clinical and scientific methodologies and assays may be used to assess the reduction, regression, or remission of an infection or its symptoms. “Treatment” refers to both therapeutic treatment and prophylactic or preventative measures. Those in need of treatment include those already with the infection as well as those prone to have the disease or those in whom the disease is to be prevented.

II. COMPOUNDS

A. DIPHOSPHINO METALLIC COMPLEXES

Disclosed are diphosphino-organometallic complexes or compounds. In some forms, the compound has the formula:

wherein:

r is an integer between 0 and 5, inclusive, preferably 2;

q is an integer between 1 and 6, inclusive, preferably 1;

M is a transition metal, preferably iridium;

the oxidation state of M is between +1 and +7, inclusive, preferably +3;

R ₁’, R ₂’, R ₃’, R ₄’, R ₅’, R ₆’, R ₇’, and R ₈’are independently hydrogen, substituted aryl, unsubstituted aryl, substituted heteroaryl, unsubstituted heteroaryl, substituted C ₃-C ₂₀ cycloalkyl, unsubstituted C ₃-C ₂₀ cycloalkyl, substituted polyaryl, unsubstituted polyaryl, substituted polyheteroaryl, unsubstituted polyheteroaryl, substituted C ₃-C ₂₀ heterocyclyl, unsubstituted C ₃-C ₂₀ heterocyclyl, substituted C ₃-C ₂₀ cycloalkenyl, unsubstituted C ₃-C ₂₀ cycloalkenyl, substituted C ₃-C ₂₀ cycloalkynyl, unsubstituted C ₃-C ₂₀ cycloalkynyl, substituted alkyl, unsubstituted alkyl, substituted alkenyl, unsubstituted alkenyl, substituted alkynyl, unsubstituted alkynyl, substituted alkoxy, unsubstituted alkoxy, substituted aroxy, unsubstituted aroxy, substituted alkylthio, unsubstituted alkylthio, substituted arylthio, unsubstituted arylthio, substituted carbonyl, unsubstituted carbonyl, substituted carboxyl, unsubstituted carboxyl, substituted amino, unsubstituted amino, substituted amido, unsubstituted amido, substituted sulfonyl, unsubstituted sulfonyl, substituted sulfonic acid, unsubstituted sulfonic acid, substituted phosphoryl, unsubstituted phosphoryl, substituted phosphonyl, unsubstituted phosphonyl, halogen, cyano, or hydroxyl, preferably R ₁’, R ₂’, R ₅’, and R ₆’are unsubstituted aryl, substituted aryl, unsubstituted C ₃-C ₆ cycloalkyl, substituted C ₃-C ₆ cycloalkyl; R ₇’and R ₈’are independently substituted aryl, unsubstituted aryl, substituted heteroaryl, unsubstituted heteroaryl, substituted polyaryl, unsubstituted polyaryl, substituted polyheteroaryl, unsubstituted polyheteroaryl;

A’is a bond, absent, substituted aryl, unsubstituted aryl, substituted heteroaryl, unsubstituted heteroaryl, substituted C ₃-C ₂₀ cycloalkyl, unsubstituted C ₃-C ₂₀ cycloalkyl, substituted polyaryl, unsubstituted polyaryl, substituted polyheteroaryl, unsubstituted polyheteroaryl, substituted C ₃-C ₂₀ heterocyclyl, unsubstituted C ₃-C ₂₀ heterocyclyl, substituted C ₃-C ₂₀ cycloalkenyl, unsubstituted C ₃-C ₂₀ cycloalkenyl, substituted C ₃-C ₂₀ cycloalkynyl, unsubstituted C ₃-C ₂₀ cycloalkynyl, substituted alkyl, unsubstituted alkyl, substituted alkenyl, unsubstituted alkenyl, substituted alkynyl, unsubstituted alkynyl, substituted alkoxy, unsubstituted alkoxy, substituted aroxy, unsubstituted aroxy, substituted alkylthio, unsubstituted alkylthio, substituted arylthio, unsubstituted arylthio, substituted carbonyl, unsubstituted carbonyl, substituted carboxyl, unsubstituted carboxyl, substituted amino, unsubstituted amino, substituted amido, unsubstituted amido, substituted sulfonyl, unsubstituted sulfonyl, substituted sulfonic acid, unsubstituted sulfonic acid, substituted phosphoryl, unsubstituted phosphoryl, substituted phosphonyl, or unsubstituted phosphonyl, preferably a bond, wherein the bond is a single bond.

In some forms, R ₃’and R ₄’together form R ₉’, wherein,

R ₉’is unsubstituted alkylene, substituted alkylene, unsubstituted alkyl, substituted alkyl, substituted aryl, unsubstituted aryl, substituted heteroaryl, unsubstituted heteroaryl, substituted C ₃-C ₂₀ cycloalkyl, unsubstituted C ₃-C ₂₀ cycloalkyl, substituted polyaryl, unsubstituted polyaryl, substituted polyheteroaryl, unsubstituted polyheteroaryl, substituted C ₃-C ₂₀ heterocyclyl, unsubstituted C ₃-C ₂₀ heterocyclyl, substituted C ₃-C ₂₀ cycloalkenyl, unsubstituted C ₃-C ₂₀ cycloalkenyl, substituted C ₃-C ₂₀ cycloalkynyl, unsubstituted C ₃-C ₂₀ cycloalkynyl, substituted alkenyl, unsubstituted alkenyl, substituted alkynyl, unsubstituted alkynyl, substituted alkoxy, unsubstituted alkoxy, substituted aroxy, unsubstituted aroxy, substituted alkylthio, unsubstituted alkylthio, substituted arylthio, unsubstituted arylthio, substituted carbonyl, unsubstituted carbonyl, substituted carboxyl, unsubstituted carboxyl, substituted amino, unsubstituted amino, substituted amido, unsubstituted amido, substituted sulfonyl, unsubstituted sulfonyl, substituted sulfonic acid, unsubstituted sulfonic acid, substituted phosphoryl, unsubstituted phosphoryl, substituted phosphonyl, or unsubstituted phosphonyl, preferably unsubstituted C ₁-C ₆ alkylene or substituted C ₁-C ₆ alkylene, more preferably unsubstituted C ₁-C ₆ alkylene. R ₉’can be unsubstituted C ₁ alkylene, substituted C ₁ alkylene, unsubstituted C ₂ alkylene, substituted C ₂ alkylene, unsubstituted C ₃ alkylene, substituted C ₃ alkylene, unsubstituted C ₄ alkylene, substituted C ₄ alkylene, unsubstituted C ₅ alkylene, substituted C ₅ alkylene, unsubstituted C ₆ alkylene, or substituted C ₆ alkylene. Preferably R ₉’can be unsubstituted C ₁ alkylene, unsubstituted C ₂ alkylene, unsubstituted C ₃ alkylene, unsubstituted C ₄ alkylene, or unsubstituted C ₅ alkylene.

In some forms, R ₇’-A’-R ₈’is not 2- (2, 4-difluorophenyl) pyridine or 2-phenylpyridine, 2-phenylpyridine, 2- (2, 4-difluorophenyl) pyridine, 2- (2, 4- difluorophenyl) -4-fluoropyridine, halogen-substituted 2-phenylpyridine, fluorosubstituted 2-phenylpyridine, 2-phenylpyridine, or fluorosubstituted 2-phenylpyridine.

In some forms, M is not iridium.

In some forms, P (R ₁’R ₂’R ₃’) and P (R ₄’R ₅’R ₆’) together do not form 1, 2-bis(diphenylphosphino) ethane, 1, 3-bis (diphenylphosphino) propane, or 1, 2-bis(diphenylphosphino) methane, and wherein at least one of R ₁’, R ₂’, R ₅’, and R ₆’is not p-tolyl, phenyl, or alkoxy.

In some forms, (i) R ₇’-A’-R ₈’is not 2- (2, 4-difluorophenyl) pyridine or 2-phenylpyridine, 2-phenylpyridine, 2- (2, 4-difluorophenyl) pyridine, 2- (2, 4-difluorophenyl) -4-fluoropyridine, halogen-substituted 2-phenylpyridine, fluorosubstituted 2-phenylpyridine, 2-phenylpyridine, or fluorosubstituted 2-phenylpyridine; (ii) M is not iridium; (iii) P (R ₁’R ₂’R ₃’) and P (R ₄’R ₅’R ₆’) together do not form 1, 2-bis (diphenylphosphino) ethane, 1, 3-bis (diphenylphosphino) propane, or 1, 2-bis (diphenylphosphino) methane, and at least one of R ₁’, R ₂’, R ₅’, and R ₆’is not p-tolyl, phenyl, or alkoxy; or (iv) combinations thereof.

In some forms, (i) R ₇’-A’-R ₈’is not 2- (2, 4-difluorophenyl) pyridine or 2-phenylpyridine, 2-phenylpyridine, 2- (2, 4-difluorophenyl) pyridine, 2- (2, 4-difluorophenyl) -4-fluoropyridine, halogen-substituted 2-phenylpyridine, fluorosubstituted 2-phenylpyridine, 2-phenylpyridine, or fluorosubstituted 2-phenylpyridine; (ii) M is not iridium; and (iii) P (R ₁’R ₂’R ₃’) and P (R ₄’R ₅’R ₆’) together do not form 1, 2-bis (diphenylphosphino) ethane, 1, 3-bis (diphenylphosphino) propane, or 1, 2-bis (diphenylphosphino) methane, and at least one of R ₁’, R ₂’, R ₅’, and R ₆’is not p-tolyl, phenyl, or alkoxy.

In some forms, when M is iridium and P (R ₁’R ₂’R ₃’) and P (R ₄’R ₅’R ₆’) together form 1, 2-bis (diphenylphosphino) ethane, R ₇’-A’-R ₈’is not 2- (2, 4-difluorophenyl) pyridine or 2-phenylpyridine. In some forms, when M is iridium and P (R ₁’R ₂’R ₃’) and P (R ₄’R ₅’R ₆’) together form 1, 3-bis (diphenylphosphino) propane, R ₇’-A’-R ₈’is not 2-phenylpyridine. In some forms, when M is iridium, R ₁’, R ₂’, R ₅’, and R ₆’are p-tolyl, and R ₃’and R ₄’together form 1, 1’-binaphthalene, R ₇’-A’-R ₈’is not 2- (2, 4- difluorophenyl) pyridine. In some forms, when M is iridium and P (R ₁’R ₂’R ₃’) and P (R ₄’R ₅’R ₆’) together form 1, 2-bis (diphenylphosphino) methane, R ₇’-A’-R ₈’is not 2- (2, 4-difluorophenyl) -4-fluoropyridine. In some forms, when M is iridium, R ₁’, R ₂’, R ₅’, and R ₆’are phenyl, and R ₃’and R ₄’together form benzene, ethene, or dimethyldiphenyl silane, R ₇’-A’-R ₈’is not halogen-substituted 2-phenylpyridine or fluorosubstituted 2-phenylpyridine. In some forms, when M is iridium and R ₁’, R ₂’, R ₃’, R ₄’, R ₅’, and R ₆’are alkoxy, C ₁-C ₅ alkoxy, or ethoxy, R ₇’-A’-R ₈’is not halogen-substituted 2-phenylpyridine or fluorosubstituted 2-phenylpyridine.

In some forms, (i) when M is iridium and P (R ₁’R ₂’R ₃’) and P (R ₄’R ₅’R ₆’) together form 1, 2-bis (diphenylphosphino) ethane, R ₇’-A’-R ₈’is not 2- (2, 4-difluorophenyl) pyridine or 2-phenylpyridine; (ii) when M is iridium and P (R ₁’R ₂’R ₃’) and P (R ₄’R ₅’R ₆’) together form 1, 3-bis(diphenylphosphino) propane, R ₇’-A’-R ₈’is not 2-phenylpyridine; (iii) when M is iridium, R ₁’, R ₂’, R ₅’, and R ₆’are p-tolyl, and R ₃’and R ₄’together form 1, 1’-binaphthalene, R ₇’-A’-R ₈’is not 2- (2, 4-difluorophenyl) pyridine; (iv) when M is iridium and P (R ₁’R ₂’R ₃’) and P (R ₄’R ₅’R ₆’) together form 1, 2-bis (diphenylphosphino) methane, R ₇’-A’-R ₈’is not 2- (2, 4-difluorophenyl) -4-fluoropyridine; (v) when M is iridium, R ₁’, R ₂’, R ₅’, and R ₆’are phenyl, and R ₃’and R ₄’together form benzene, ethene, or dimethyldiphenyl silane, R ₇’-A’-R ₈’is not halogen-substituted 2-phenylpyridine or fluorosubstituted 2-phenylpyridine; (vi) when M is iridium and R ₁’, R ₂’, R ₃’, R ₄’, R ₅’, and R ₆’are alkoxy, C ₁-C ₅ alkoxy, or ethoxy, R ₇’-A’-R ₈’is not halogen-substituted 2-phenylpyridine or fluorosubstituted 2-phenylpyridine; or (vii) combinations thereof.

In some forms, (i) when M is iridium and P (R ₁’R ₂’R ₃’) and P (R ₄’R ₅’R ₆’) together form 1, 2-bis (diphenylphosphino) ethane, R ₇’-A’-R ₈’is not 2- (2, 4-difluorophenyl) pyridine or 2-phenylpyridine; (ii) when M is iridium and P (R ₁’R ₂’R ₃’) and P (R ₄’R ₅’R ₆’) together form 1, 3-bis (diphenylphosphino) propane, R ₇’-A’-R ₈’is not 2-phenylpyridine; (iii) when M is iridium, R ₁’, R ₂’, R ₅’, and R ₆’are p-tolyl, and R ₃’and R ₄’together form 1, 1’-binaphthalene, R ₇’-A’-R ₈’is not 2- (2, 4-difluorophenyl) pyridine; (iv) when M is iridium and P (R ₁’R ₂’R ₃’) and P (R ₄’R ₅’R ₆’) together form 1, 2-bis (diphenylphosphino) methane, R ₇’-A’-R ₈’is not 2- (2, 4-difluorophenyl) -4-fluoropyridine; (v) when M is iridium, R ₁’, R ₂’, R ₅’, and R ₆’are phenyl, and R ₃’and R ₄’together form benzene, ethene, or dimethyldiphenyl silane, R ₇’-A’-R ₈’is not halogen-substituted 2-phenylpyridine or fluorosubstituted 2-phenylpyridine; and (vi) when M is iridium and R ₁’, R ₂’, R ₃’, R ₄’, R ₅’, and R ₆’are alkoxy, C ₁-C ₅ alkoxy, or ethoxy, R ₇’-A’-R ₈’is not halogen-substituted 2-phenylpyridine or fluorosubstituted 2-phenylpyridine.

In some forms, M is selected from the group consisting of iridium, rhodium, cobalt, iron, ruthenium, osmium, nickel, palladium, platinum, manganese, technetium, rhenium, chromium, molybdenum, tungsten, vanadium, niobium, tantalum, titanium, zirconium, hafnium, scandium, yttrium, copper, silver, gold, and zinc. Preferably, M is iridium.

In some forms, R ₇’, and R ₈’are independently substituted aryl, unsubstituted aryl, substituted heteroaryl, unsubstituted heteroaryl, substituted C ₃-C ₂₀ cycloalkyl, unsubstituted C ₃-C ₂₀ cycloalkyl, substituted polyaryl, unsubstituted polyaryl, substituted polyheteroaryl, unsubstituted polyheteroaryl, substituted C ₃-C ₂₀ heterocyclyl, unsubstituted C ₃-C ₂₀ heterocyclyl, substituted C ₃-C ₂₀ cycloalkenyl, unsubstituted C ₃-C ₂₀ cycloalkenyl, substituted C ₃-C ₂₀ cycloalkynyl, unsubstituted C ₃-C ₂₀ cycloalkynyl, substituted alkyl, unsubstituted alkyl, substituted alkenyl, unsubstituted alkenyl, substituted alkynyl, unsubstituted alkynyl, substituted alkoxy, unsubstituted alkoxy, substituted aroxy, unsubstituted aroxy, substituted alkylthio, unsubstituted alkylthio, substituted arylthio, unsubstituted arylthio, substituted carbonyl, unsubstituted carbonyl, substituted carboxyl, unsubstituted carboxyl, substituted amino, unsubstituted amino, substituted amido, unsubstituted amido, substituted sulfonyl, unsubstituted sulfonyl, substituted sulfonic acid, unsubstituted sulfonic acid, substituted phosphoryl, unsubstituted phosphoryl, substituted phosphonyl, unsubstituted phosphonyl, halogen, cyano, or hydroxyl. Exemplary aryl or heteroaryl groups include, but are not limited to, benzene, naphthalene, thiophene, benzothiophene, anthracene, pyrene, furan, pyrimidine, pyrrole, pyridine, fluorene, carbozole, carborane, isoquinoline, 1-isoquinoline, 2-quinoline, and benzothiazole.

In some forms, R ₃’and R ₄’together form R ₉’, wherein R ₉’is unsubstituted alkylene, substituted alkylene, unsubstituted alkyl, substituted alkyl, substituted aryl, unsubstituted aryl, substituted heteroaryl, unsubstituted heteroaryl, substituted C ₃-C ₂₀ cycloalkyl, unsubstituted C ₃-C ₂₀ cycloalkyl, substituted polyaryl, unsubstituted polyaryl, substituted polyheteroaryl, unsubstituted polyheteroaryl, substituted C ₃-C ₂₀ heterocyclyl, unsubstituted C ₃-C ₂₀ heterocyclyl, substituted C ₃-C ₂₀ cycloalkenyl, unsubstituted C ₃-C ₂₀ cycloalkenyl, substituted C ₃-C ₂₀ cycloalkynyl, unsubstituted C ₃-C ₂₀ cycloalkynyl, substituted alkenyl, unsubstituted alkenyl, substituted alkynyl, or unsubstituted alkynyl.

In some forms, A’is a single bond; and R ₁’, R ₂’, R ₃’, R ₄’, R ₅’, R ₆’, R ₇’, and R ₈’are independently substituted aryl, unsubstituted aryl, substituted heteroaryl, unsubstituted heteroaryl, substituted C ₃-C ₂₀ cycloalkyl, unsubstituted C ₃-C ₂₀ cycloalkyl, substituted polyaryl, unsubstituted polyaryl, substituted polyheteroaryl, unsubstituted polyheteroaryl, substituted C ₃-C ₂₀ heterocyclyl, unsubstituted C ₃-C ₂₀ heterocyclyl, substituted C ₃-C ₂₀ cycloalkenyl, unsubstituted C ₃-C ₂₀ cycloalkenyl, substituted C ₃-C ₂₀ cycloalkynyl, or unsubstituted C ₃-C ₂₀ cycloalkynyl.

In some forms, R ₇’, and R ₈’are independently aryl, unsubstituted aryl, substituted heteroaryl, unsubstituted heteroaryl, substituted polyaryl, unsubstituted polyaryl, substituted polyheteroaryl, or unsubstituted polyheteroaryl.

In some forms, M is iridium and the oxidation state of iridium is +3. In some forms, the compound further comprises a counter-ion. In some forms, q is 1, and r is 2. In some forms, R ₉’is unsubstituted C ₁-C ₆ alkylene or substituted C ₁-C ₆ alkylene.

In some forms, each R ₇’is independently an unsubstituted heteroaryl, substituted heteroaryl, unsubstituted polyheteroaryl, or substituted polyheteroaryl, wherein the unsubstituted heteroaryl, substituted heteroaryl, unsubstituted polyheteroaryl, or substituted polyheteroaryl comprise one or more nitrogen atoms.

In some forms, each R ₈’, is independently an unsubstituted aryl, substituted aryl, unsubstituted polyaryl, or substituted polyaryl.

In some forms, R ₁’, R ₂’, R ₅’, and R ₆’are independently an unsubstituted aryl, substituted aryl, unsubstituted polyaryl, substituted polyaryl, independently a substituted C ₃-C ₂₀ cycloalkyl, unsubstituted C ₃-C ₂₀ cycloalkyl, substituted C ₃-C ₂₀ heterocyclyl, unsubstituted C ₃-C ₂₀ heterocyclyl, substituted C ₃-C ₂₀ cycloalkenyl, unsubstituted C ₃-C ₂₀ cycloalkenyl, substituted C ₃-C ₂₀ cycloalkynyl, or unsubstituted C ₃-C ₂₀ cycloalkynyl.

In some forms, each R ₇’is independently an unsubstituted heteroaryl, substituted heteroaryl, unsubstituted polyheteroaryl, or substituted polyheteroaryl, wherein the unsubstituted heteroaryl, substituted heteroaryl, unsubstituted polyheteroaryl, or substituted polyheteroaryl comprise one or more nitrogen atoms; each R ₈’, is independently an unsubstituted aryl, substituted aryl, unsubstituted polyaryl, or substituted polyaryl; R ₁’, R ₂’, R ₅’, and R ₆’are independently an unsubstituted aryl, substituted aryl, unsubstituted polyaryl, substituted polyaryl, independently a substituted C ₃-C ₂₀ cycloalkyl, unsubstituted C ₃-C ₂₀ cycloalkyl, substituted C ₃-C ₂₀ heterocyclyl, unsubstituted C ₃-C ₂₀ heterocyclyl, substituted C ₃-C ₂₀ cycloalkenyl, unsubstituted C ₃-C ₂₀ cycloalkenyl, substituted C ₃-C ₂₀ cycloalkynyl, or unsubstituted C ₃-C ₂₀ cycloalkynyl; or combinations thereof.

In some forms, each R ₇’is independently an unsubstituted heteroaryl, substituted heteroaryl, unsubstituted polyheteroaryl, or substituted polyheteroaryl, wherein the unsubstituted heteroaryl, substituted heteroaryl, unsubstituted polyheteroaryl, or substituted polyheteroaryl comprise one or more nitrogen atoms; each R ₈’, is independently an unsubstituted aryl, substituted aryl, unsubstituted polyaryl, or substituted polyaryl; and R ₁’, R ₂’, R ₅’, and R ₆’are independently an unsubstituted aryl, substituted aryl, unsubstituted polyaryl, substituted polyaryl, independently a substituted C ₃-C ₂₀ cycloalkyl, unsubstituted C ₃-C ₂₀ cycloalkyl, substituted C ₃-C ₂₀ heterocyclyl, unsubstituted C ₃-C ₂₀ heterocyclyl, substituted C ₃-C ₂₀ cycloalkenyl, unsubstituted C ₃-C ₂₀ cycloalkenyl, substituted C ₃-C ₂₀ cycloalkynyl, or unsubstituted C ₃-C ₂₀ cycloalkynyl.

In some forms, the compound has the formula:

where R ₁-R ₃₆ can independently be hydrogen, substituted aryl, unsubstituted aryl, substituted heteroaryl, unsubstituted heteroaryl, substituted C ₃-C ₂₀ cycloalkyl, unsubstituted C ₃-C ₂₀ cycloalkyl, substituted polyaryl, unsubstituted polyaryl, substituted polyheteroaryl, unsubstituted polyheteroaryl, substituted C ₃-C ₂₀ heterocyclyl, unsubstituted C ₃-C ₂₀ heterocyclyl, substituted C ₃-C ₂₀ cycloalkenyl, unsubstituted C ₃-C ₂₀ cycloalkenyl, substituted C ₃-C ₂₀ cycloalkynyl, unsubstituted C ₃-C ₂₀ cycloalkynyl, substituted alkyl, unsubstituted alkyl, substituted alkenyl, unsubstituted alkenyl, substituted alkynyl, unsubstituted alkynyl, substituted alkoxy, unsubstituted alkoxy, substituted aroxy, unsubstituted aroxy, substituted alkylthio, unsubstituted alkylthio, substituted arylthio, unsubstituted arylthio, substituted carbonyl, unsubstituted carbonyl, substituted carboxyl, unsubstituted carboxyl, substituted amino, unsubstituted amino, substituted amido, unsubstituted amido, substituted sulfonyl, unsubstituted sulfonyl, substituted sulfonic acid, unsubstituted sulfonic acid, substituted phosphoryl, unsubstituted phosphoryl, substituted phosphonyl, unsubstituted phosphonyl, halogen, cyano, or hydroxyl; R ₃₇ can be R ₉’as described above; n can be +1 or +2; y can be +1 or +2; A is a counter-ion; and b can be -1 or -2. In some forms, n can be +1; b can be -1; and y can be 1.

In some forms, R ₁-R ₃₆ can independently be substituted alkyl, unsubstituted alkyl, or hydrogen. In some forms, R ₁-R ₃₆ can each be hydrogen. In some forms, A is Cl, hexaflurophosphate (PF ₆) , trimethanesulfonate (OTf) , or a pharmaceutically acceptable anion. In some forms of Formula II, R ₇ and R ₁₅ can be independently C ₁-C ₄ substituted alkyl or unsubstituted alkyl.

In some forms, R ₃₇ is preferably unsubstituted C ₁-C ₆ alkylene or substituted C ₁-C ₆ alkylene, more preferably unsubstituted C ₁-C ₆ alkylene; R ₉’can be unsubstituted C ₁ alkylene, substituted C ₁ alkylene, unsubstituted C ₂ alkylene, substituted C ₂ alkylene, unsubstituted C ₃ alkylene, substituted C ₃ alkylene, unsubstituted C ₄ alkylene, substituted C ₄ alkylene, unsubstituted C ₅ alkylene, substituted C ₅ alkylene, unsubstituted C ₆ alkylene, or substituted C ₆ alkylene. Preferably R ₉’can be unsubstituted C ₁ alkylene, unsubstituted C ₂ alkylene, unsubstituted C ₃ alkylene, unsubstituted C ₄ alkylene, or unsubstituted C ₅ alkylene.

In some forms, the compound has the formula:

where R ₁-R ₅₆ can independently be hydrogen, substituted aryl, unsubstituted aryl, substituted heteroaryl, unsubstituted heteroaryl, substituted C ₃-C ₂₀ cycloalkyl, unsubstituted C ₃-C ₂₀ cycloalkyl, substituted polyaryl, unsubstituted polyaryl, substituted polyheteroaryl, unsubstituted polyheteroaryl, substituted C ₃-C ₂₀ heterocyclyl, unsubstituted C ₃-C ₂₀ heterocyclyl, substituted C ₃-C ₂₀ cycloalkenyl, unsubstituted C ₃-C ₂₀ cycloalkenyl, substituted C ₃-C ₂₀ cycloalkynyl, unsubstituted C ₃-C ₂₀ cycloalkynyl, substituted alkyl, unsubstituted alkyl, substituted alkenyl, unsubstituted alkenyl, substituted alkynyl, unsubstituted alkynyl, substituted alkoxy, unsubstituted alkoxy, substituted aroxy, unsubstituted aroxy, substituted alkylthio, unsubstituted alkylthio, substituted arylthio, unsubstituted arylthio, substituted carbonyl, unsubstituted carbonyl, substituted carboxyl, unsubstituted carboxyl, substituted amino, unsubstituted amino, substituted amido, unsubstituted amido, substituted sulfonyl, unsubstituted sulfonyl, substituted sulfonic acid, unsubstituted sulfonic acid, substituted phosphoryl, unsubstituted phosphoryl, substituted phosphonyl, unsubstituted phosphonyl, halogen, cyano, or hydroxyl; R ₅₇ is R ₉’as described above; n can be +1 or +2; y can be +1 or +2; A is a counter-ion; and b can be -1 or -2. In some forms, n can be +1; b can be -1; and y can be 1.

In some forms, R ₁-R ₅₆ can independently be substituted alkyl, unsubstituted alkyl, or hydrogen. In some forms, R ₁-R ₅₆ can each be hydrogen. In some forms, A is Cl, PF ₆, OTf, or a pharmaceutically acceptable anion.

In some forms, R ₅₇ is preferably unsubstituted C ₁-C ₆ alkylene or substituted C ₁-C ₆ alkylene, more preferably unsubstituted C ₁-C ₆ alkylene; R ₉’can be unsubstituted C ₁ alkylene, substituted C ₁ alkylene, unsubstituted C ₂ alkylene, substituted C ₂ alkylene, unsubstituted C ₃ alkylene, substituted C ₃ alkylene, unsubstituted C ₄ alkylene, substituted C ₄ alkylene, unsubstituted C ₅ alkylene, substituted C ₅ alkylene, unsubstituted C ₆ alkylene, or substituted C ₆ alkylene. Preferably R ₉’can be unsubstituted C ₁ alkylene, unsubstituted C ₂ alkylene, unsubstituted C ₃ alkylene, unsubstituted C ₄ alkylene, or unsubstituted C ₅ alkylene.

In some forms, the compound has the formula:

where R ₁-R ₄₄ are independently hydrogen, substituted aryl, unsubstituted aryl, substituted heteroaryl, unsubstituted heteroaryl, substituted C ₃-C ₂₀ cycloalkyl, unsubstituted C ₃-C ₂₀ cycloalkyl, substituted polyaryl, unsubstituted polyaryl, substituted polyheteroaryl, unsubstituted polyheteroaryl, substituted C ₃-C ₂₀ heterocyclyl, unsubstituted C ₃-C ₂₀ heterocyclyl, substituted C ₃-C ₂₀ cycloalkenyl, unsubstituted C ₃-C ₂₀ cycloalkenyl, substituted C ₃-C ₂₀ cycloalkynyl, unsubstituted C ₃-C ₂₀ cycloalkynyl, substituted alkyl, unsubstituted alkyl, substituted alkenyl, unsubstituted alkenyl, substituted alkynyl, unsubstituted alkynyl, substituted alkoxy, unsubstituted alkoxy, substituted aroxy, unsubstituted aroxy, substituted alkylthio, unsubstituted alkylthio, substituted arylthio, unsubstituted arylthio, substituted carbonyl, unsubstituted carbonyl, substituted carboxyl, unsubstituted carboxyl, substituted amino, unsubstituted amino, substituted amido, unsubstituted amido, substituted sulfonyl, unsubstituted sulfonyl, substituted sulfonic acid, unsubstituted sulfonic acid, substituted phosphoryl, unsubstituted phosphoryl, substituted phosphonyl, unsubstituted phosphonyl, halogen, cyano, or hydroxyl; R ₄₅ is R ₉’as described above; n can be +1 or +2; y can be +1 or +2; A is a counter-ion; and b can be -1 or -2. In some forms, n can be +1; b can be -1; and y can be 1.

In some forms, R ₁-R ₅₄ can independently be substituted alkyl, unsubstituted alkyl, or hydrogen. In some forms, R ₁-R ₅₄ can each be hydrogen. In some forms, A is Cl, PF ₆, OTf, or a pharmaceutically acceptable anion.

In some forms, R ₄₅ is preferably unsubstituted C ₁-C ₆ alkylene or substituted C ₁-C ₆ alkylene, more preferably unsubstituted C ₁-C ₆ alkylene. R ₉’can be unsubstituted C ₁ alkylene, substituted C ₁ alkylene, unsubstituted C ₂ alkylene, substituted C ₂ alkylene, unsubstituted C ₃ alkylene, substituted C ₃ alkylene, unsubstituted C ₄ alkylene, substituted C ₄ alkylene, unsubstituted C ₅ alkylene, substituted C ₅ alkylene, unsubstituted C ₆ alkylene, or substituted C ₆ alkylene. Preferably R ₉’can be unsubstituted C ₁ alkylene, unsubstituted C ₂ alkylene, unsubstituted C ₃ alkylene, unsubstituted C ₄ alkylene, or unsubstituted C ₅ alkylene.

In some forms, the compound has the formula:

where R ₁-R ₄₀ are independently hydrogen, substituted aryl, unsubstituted aryl, substituted heteroaryl, unsubstituted heteroaryl, substituted C ₃-C ₂₀ cycloalkyl, unsubstituted C ₃-C ₂₀ cycloalkyl, substituted polyaryl, unsubstituted polyaryl, substituted polyheteroaryl, unsubstituted polyheteroaryl, substituted C ₃-C ₂₀ heterocyclyl, unsubstituted C ₃-C ₂₀ heterocyclyl, substituted C ₃-C ₂₀ cycloalkenyl, unsubstituted C ₃-C ₂₀ cycloalkenyl, substituted C ₃-C ₂₀ cycloalkynyl, unsubstituted C ₃-C ₂₀ cycloalkynyl, substituted alkyl, unsubstituted alkyl, substituted alkenyl, unsubstituted alkenyl, substituted alkynyl, unsubstituted alkynyl, substituted alkoxy, unsubstituted alkoxy, substituted aroxy, unsubstituted aroxy, substituted alkylthio, unsubstituted alkylthio, substituted arylthio, unsubstituted arylthio, substituted carbonyl, unsubstituted carbonyl, substituted carboxyl, unsubstituted carboxyl, substituted amino, unsubstituted amino, substituted amido, unsubstituted amido, substituted sulfonyl, unsubstituted sulfonyl, substituted sulfonic acid, unsubstituted sulfonic acid, substituted phosphoryl, unsubstituted phosphoryl, substituted phosphonyl, unsubstituted phosphonyl, halogen, cyano, or hydroxyl; R ₄₁ is R ₉’as described above; n can be +1 or +2; y can be +1 or +2; A is a counter-ion; and b can be -1 or -2. In some forms, n can be +1; b can be -1; and y can be 1.

In some forms, R ₁-R ₃₆ can independently be substituted alkyl, unsubstituted alkyl, or hydrogen. In some forms, R ₁-R ₃₆ can each be hydrogen. In some forms, A is Cl, PF ₆, OTf, or a pharmaceutically acceptable anion.

In some forms, R ₄₁ is preferably unsubstituted C ₁-C ₆ alkylene or substituted C ₁-C ₆ alkylene, more preferably unsubstituted C ₁-C ₆ alkylene. R ₉’can be unsubstituted C ₁ alkylene, substituted C ₁ alkylene, unsubstituted C ₂ alkylene, substituted C ₂ alkylene, unsubstituted C ₃ alkylene, substituted C ₃ alkylene, unsubstituted C ₄ alkylene, substituted C ₄ alkylene, unsubstituted C ₅ alkylene, substituted C ₅ alkylene, unsubstituted C ₆ alkylene, or substituted C ₆ alkylene. Preferably R ₉’can be unsubstituted C ₁ alkylene, unsubstituted C ₂ alkylene, unsubstituted C ₃ alkylene, unsubstituted C ₄ alkylene, or unsubstituted C ₅ alkylene.

In some forms, the compound has the formula:

where R ₁-R ₃₄ are independently hydrogen, substituted aryl, unsubstituted aryl, substituted heteroaryl, unsubstituted heteroaryl, substituted C ₃-C ₂₀ cycloalkyl, unsubstituted C ₃-C ₂₀ cycloalkyl, substituted polyaryl, unsubstituted polyaryl, substituted polyheteroaryl, unsubstituted polyheteroaryl, substituted C ₃-C ₂₀ heterocyclyl, unsubstituted C ₃-C ₂₀ heterocyclyl, substituted C ₃-C ₂₀ cycloalkenyl, unsubstituted C ₃-C ₂₀ cycloalkenyl, substituted C ₃-C ₂₀ cycloalkynyl, unsubstituted C ₃-C ₂₀ cycloalkynyl, substituted alkyl, unsubstituted alkyl, substituted alkenyl, unsubstituted alkenyl, substituted alkynyl, unsubstituted alkynyl, substituted alkoxy, unsubstituted alkoxy, substituted aroxy, unsubstituted aroxy, substituted alkylthio, unsubstituted alkylthio, substituted arylthio, unsubstituted arylthio, substituted carbonyl, unsubstituted carbonyl, substituted carboxyl, unsubstituted carboxyl, substituted amino, unsubstituted amino, substituted amido, unsubstituted amido, substituted sulfonyl, unsubstituted sulfonyl, substituted sulfonic acid, unsubstituted sulfonic acid, substituted phosphoryl, unsubstituted phosphoryl, substituted phosphonyl, unsubstituted phosphonyl, halogen, cyano, or hydroxyl; R ₃₅ is R ₉’as described above; n can be +1 or +2; y can be +1 or +2; A is a counter-ion; and b can be -1 or -2. In some forms, n can be +1; b can be -1; and y can be 1.

In some forms, R ₃₅ is preferably unsubstituted C ₁-C ₆ alkylene or substituted C ₁-C ₆ alkylene, more preferably unsubstituted C ₁-C ₆ alkylene. R ₉’can be unsubstituted C ₁ alkylene, substituted C ₁ alkylene, unsubstituted C ₂ alkylene, substituted C ₂ alkylene, unsubstituted C ₃ alkylene, substituted C ₃ alkylene, unsubstituted C ₄ alkylene, substituted C ₄ alkylene, unsubstituted C ₅ alkylene, substituted C ₅ alkylene, unsubstituted C ₆ alkylene, or substituted C ₆ alkylene. Preferably R ₉’can be unsubstituted C ₁ alkylene, unsubstituted C ₂ alkylene, unsubstituted C ₃ alkylene, unsubstituted C ₄ alkylene, or unsubstituted C ₅ alkylene.

In some aspects, the compound can be [ (phenylpyridine) ₂Ir (DPPE) ] PF ₆, [ (phenylpyridine) ₂Ir (DPPE) ] Cl, [ (phenylpyridine) ₂Ir (DCPE) ] PF ₆, [ (phenylpyridine) ₂Ir (DCPE) ] Cl, [ (phenylpyridine ) ₂Ir (DPPP) ] PF ₆, [ (phenylpyridine ) ₂Ir (DPPP) ] Cl, [ (2-phenylbenzothiazole) ₂Ir (DPPE) ] PF ₆, [ (2-phenylbenzothiazole) ₂Ir (DPPE) ] Cl, [ (2-phenyl-6- (trifluoromethyl) benzothiazole) ₂Ir (DPPE) ] PF ₆, [ (2-phenyl-6- (trifluoromethyl) benzothiazole) ₂Ir (DPPE) ] Cl, [ (1- (2-naphthyl) isoquinoline) ₂Ir (DPPE) ] PF ₆, [ (1- (2-naphthyl) isoquinoline) ₂Ir (DPPE) ] Cl, [ (1- (2-thienyl) isoquinoline) ₂Ir (DPPE) ] PF ₆, [ (1- (2-thienyl) isoquinoline) ₂Ir (DPPE) ] Cl, [ (2- (2-Naphthalenyl) pyridine) ₂Ir (DPPE) ] PF ₆, [ (2- (2-Naphthalenyl) pyridine) ₂Ir (DPPE) ] PF ₆, [ (4-methyl-2- (2-thienyl) -quinoline) ₂Ir (DPPE) ] PF ₆, [ (4-methyl-2- (2-thienyl) -quinoline) ₂Ir (DPPE) ] PF ₆, [ (4- ⁿbutylphenylpyridine) ₂Ir (DPPE) ] Cl, or [ (4- ⁿbutylphenylpyridine) ₂Ir (DPPE) ] PF ₆. DPPE, DCPE, and DPPP stand for 1, 2-diphenylphosphinoethane, 1, 2-dicyclohexylphosphinoethane, and 1, 3-diphenylphosphinopropane, respectively.

In some aspects, the diphosphino complexes can be cyclometalated complexes or non-cyclometalated complexes. Preferably, the diphosphino complexes are cyclometalated.

The compounds are stable towards hydrolysis and in reducing conditions, such as in physiologically reducing conditions. The compounds display cytotoxicity against a panel of cancer cell lines. Optionally, the compounds include moieties that give rise to luminescence.

Every compound within the above definition is intended to be and should be considered to be specifically disclosed herein. Further, every subgroup that can be identified within the above definition is intended to be and should be considered to be specifically disclosed herein. As a result, it is specifically contemplated that any compound or subgroup of compounds can be either specifically included for or excluded from use or included in or excluded from a list of compounds. For example, any one or more of the compounds described herein, with a structure depicted herein, or referred to in the Tables or the Examples herein can be specifically included, excluded, or combined in any combination, in a set or subgroup of such compounds. Such specific sets, subgroups, inclusions, and exclusions can be applied to any aspect of the compositions and methods described here. For example, a set of compounds that specifically excludes one or more particular compounds can be used or applied in the context of compounds per se (for example, a list or set of compounds) , compositions including the compound (including, for example, pharmaceutical compositions) , any one or more of the disclosed methods, or combinations of these. Different sets and subgroups of compounds with such specific inclusions and exclusions can be used or applied in the context of compounds per se, compositions including one or more of the compounds, or any of the disclosed methods. All of these different sets and subgroups of compounds-and the different sets of compounds, compositions, and methods using or applying the compounds-are specifically and individual contemplated and should be considered as specifically and individually described. As an example, compound 1a. PF ₆ ( [ (phenylpyridine) ₂Ir (DPPE) ] PF ₆) and compound 1c·PF ₆ ( [ (phenylpyridine ) ₂Ir (DPPP) ] PF ₆) can be specifically included or excluded, as a group or individually, from any compounds per se (for example, a list or set of compounds) , compositions including the compound (including, for example, pharmaceutical compositions) , or any one or more of the disclosed methods, or combinations of these.

In some forms, the compounds can have the following chemical structures.

III. FORMULATIONS

The disphosphino compounds described herein can be formulated for enteral, parenteral, topical, or pulmonary administration. The compounds can be combined with one or more pharmaceutically acceptable carriers and/or excipients that are considered safe and effective and may be administered to an individual without causing undesirable biological side effects or unwanted interactions. The carrier is all components present in the pharmaceutical formulation other than the active ingredient or ingredients. See, e.g., Remington's Pharmaceutical Sciences, latest edition, by E.W. Martin Mack Pub. Co., Easton, PA, which discloses typical carriers and conventional methods of preparing pharmaceutical compositions that can be used in conjunction with the preparation of formulations of the compounds described herein and which is incorporated by reference herein. These most typically would be standard carriers for administration of compositions to humans. In one aspect, humans and non-humans, including solutions such as sterile water, saline, and buffered solutions at physiological pH. Other compounds will be administered according to standard procedures used by those skilled in the art.

These compositions can take the form of solutions, suspensions, emulsion, tablets, pills, capsules, powders, sustained-release formulations and the like.

1. Parenteral Formulations

The compounds described herein can be formulated for parenteral administration. For example, parenteral administration may include administration to a patient intravenously, intradermally, intraarterially, intraperitoneally, intralesionally, intracranially, intraarticularly, intraprostatically, intrapleurally, intratracheally, intravitreally, intratumorally, intramuscularly, subcutaneously, subconjunctivally, intravesicularly, intrapericardially, intraumbilically, by injection, and by infusion.

Parenteral formulations can be prepared as aqueous compositions using techniques known in the art. Typically, such compositions can be prepared as injectable formulations, for example, solutions or suspensions; solid forms suitable for using to prepare solutions or suspensions upon the addition of a reconstitution medium prior to injection; emulsions, such as water-in-oil (w/o) emulsions, oil-in-water (o/w) emulsions, and microemulsions thereof, liposomes, or emulsomes.

If for intravenous administration, the compositions are packaged in solutions of sterile isotonic aqueous buffer. Where necessary, the composition may also include a solubilizing agent. The components of the composition are supplied either separately or mixed together in unit dosage form, for example, as a dry lyophilized powder or concentrated solution in a hermetically sealed container such as an ampoule or sachet indicating the amount of active agent. If the composition is to be administered by infusion, it can be dispensed with an infusion bottle containing sterile pharmaceutical grade water or saline. Where the composition is administered by injection, an ampoule of sterile water or saline can be provided so that the ingredients may be mixed prior to injection.

The carrier can be a solvent or dispersion medium containing, for example, water, ethanol, one or more polyols (e.g., glycerol, propylene glycol, and liquid polyethylene glycol) , oils, such as vegetable oils (e.g., peanut oil, corn oil, sesame oil, etc. ) , and combinations thereof. The proper fluidity can be maintained, for example, by the use of a coating, such as lecithin, by the maintenance of the required particle size in the case of dispersion and/or by the use of surfactants. In many cases, it will be preferable to include isotonic agents, for example, sugars or sodium chloride.

Solutions and dispersions of the active compounds as the free acid or base or pharmacologically acceptable salts thereof can be prepared in water or another solvent or dispersing medium suitably mixed with one or more pharmaceutically acceptable excipients including, but not limited to, surfactants, dispersants, emulsifiers, pH modifying agents, viscosity modifying agents, and combination thereof.

Suitable surfactants may be anionic, cationic, amphoteric or nonionic surface-active agents. Suitable anionic surfactants include, but are not limited to, those containing carboxylate, sulfonate and sulfate ions. Examples of anionic surfactants include sodium, potassium, ammonium of long chain alkyl sulfonates and alkyl aryl sulfonates such as sodium dodecylbenzene sulfonate; dialkyl sodium sulfosuccinates, such as sodium dodecylbenzene sulfonate; dialkyl sodium sulfosuccinates, such as sodium bis- (2-ethylthioxyl) -sulfosuccinate; and alkyl sulfates such as sodium lauryl sulfate. Cationic surfactants include, but are not limited to, quaternary ammonium compounds such as benzalkonium chloride, benzethonium chloride, cetrimonium bromide, stearyl dimethylbenzyl ammonium chloride, polyoxyethylene, and coconut amine. Examples of nonionic surfactants include ethylene glycol monostearate, propylene glycol myristate, glyceryl monostearate, glyceryl stearate, polyglyceryl-4-oleate, sorbitan acylate, sucrose acylate, PEG-150 laurate, PEG-400 monolaurate, polyoxyethylene monolaurate, polysorbates, polyoxyethylene octylphenylether, PEG-1000 cetyl ether, polyoxyethylene tridecyl ether, polypropylene glycol butyl ether,

401, stearoyl monoisopropanolamide, and polyoxyethylene hydrogenated tallow amide. Examples of amphoteric surfactants include sodium N-dodecyl-β-alanine, sodium N-lauryl-β-iminodipropionate, myristoamphoacetate, lauryl betaine, and lauryl sulfobetaine.

The formulation can contain a preservative to prevent the growth of microorganisms. Suitable preservatives include, but are not limited to, parabens, chlorobutanol, phenol, sorbic acid, and thimerosal. The formulation may also contain an antioxidant to prevent degradation of the active agent (s) .

The formulation is typically buffered to a pH of 3-8 for parenteral administration upon reconstitution. Suitable buffers include, but are not limited to, phosphate buffers, acetate buffers, and citrate buffers.

Water-soluble polymers are often used in formulations for parenteral administration. Suitable water-soluble polymers include, but are not limited to, polyvinylpyrrolidone, dextran, carboxymethylcellulose, and polyethylene glycol.

Sterile injectable solutions can be prepared by incorporating the active compounds in the required amount in the appropriate solvent or dispersion medium with one or more of the excipients listed above, as required, followed by filtered sterilization. Generally, dispersions are prepared by incorporating the various sterilized active ingredients into a sterile vehicle which contains the basic dispersion medium and the required other ingredients from those listed above. In the case of sterile powders for the preparation of sterile injectable solutions, the preferred methods of preparation are vacuum-drying and freeze-drying techniques which yield a powder of the active ingredient plus any additional desired ingredient from a previously sterile-filtered solution thereof. The powders can be prepared in such a manner that the particles are porous in nature, which can increase dissolution of the particles. Methods for making porous particles are well known in the art.

(a) Controlled Release Formulations

The parenteral formulations described herein can be formulated for controlled release including immediate release, delayed release, extended release, pulsatile release, and combinations thereof.

1. Nano-and microparticles

For parenteral administration, the one or more compounds, and optional one or more additional active agents, can be incorporated into microparticles, nanoparticles, or combinations thereof that provide controlled release of the compounds and/or one or more additional active agents. In forms wherein the formulations contains two or more drugs, the drugs can be formulated for the same type of controlled release (e.g., delayed, extended, immediate, or pulsatile) or the drugs can be independently formulated for different types of release (e.g., immediate and delayed, immediate and extended, delayed and extended, delayed and pulsatile, etc. ) .

For example, the compounds and/or one or more additional active agents can be incorporated into polymeric microparticles, which provide controlled release of the drug (s) . Release of the drug (s) is controlled by diffusion of the drug (s) out of the microparticles and/or degradation of the polymeric particles by hydrolysis and/or enzymatic degradation. Suitable polymers include ethylcellulose and other natural or synthetic cellulose derivatives.

Polymers, which are slowly soluble and form a gel in an aqueous environment, such as hydroxypropyl methylcellulose or polyethylene oxide, can also be suitable as materials for drug containing microparticles. Other polymers include, but are not limited to, polyanhydrides, poly (ester anhydrides) , polyhydroxy acids, such as polylactide (PLA) , polyglycolide (PGA) , poly (lactide-co-glycolide) (PLGA) , poly-3-hydroxybutyrate (PHB) and copolymers thereof, poly-4-hydroxybutyrate (P4HB) and copolymers thereof, polycaprolactone and copolymers thereof, and combinations thereof.

Alternatively, the drug (s) can be incorporated into microparticles prepared from materials which are insoluble in aqueous solution or slowly soluble in aqueous solution, but are capable of degrading within the GI tract by means including enzymatic degradation, surfactant action of bile acids, and/or mechanical erosion. As used herein, the term “slowly soluble in water” refers to materials that are not dissolved in water within a period of 30 minutes. Preferred examples include fats, fatty substances, waxes, wax-like substances and mixtures thereof. Suitable fats and fatty substances include fatty alcohols (such as lauryl, myristyl stearyl, cetyl or cetostearyl alcohol) , fatty acids and derivatives, including but not limited to fatty acid esters, fatty acid glycerides (mono-, di-and tri-glycerides) , and hydrogenated fats. Specific examples include, but are not limited to hydrogenated vegetable oil, hydrogenated cottonseed oil, hydrogenated castor oil, hydrogenated oils available under the trade name

stearic acid, cocoa butter, and stearyl alcohol. Suitable waxes and wax-like materials include natural or synthetic waxes, hydrocarbons, and normal waxes. Specific examples of waxes include beeswax, glycowax, castor wax, carnauba wax, paraffins and candelilla wax. As used herein, a wax-like material is defined as any material, which is normally solid at room temperature and has a melting point of from about 30 to 300℃.

In some cases, it may be desirable to alter the rate of water penetration into the microparticles. To this end, rate-controlling (wicking) agents can be formulated along with the fats or waxes listed above. Examples of rate-controlling materials include certain starch derivatives (e.g., waxy maltodextrin and drum dried corn starch) , cellulose derivatives (e.g., hydroxypropylmethyl-cellulose, hydroxypropylcellulose, methylcellulose, and carboxymethyl-cellulose) , alginic acid, lactose and talc. Additionally, a pharmaceutically acceptable surfactant (for example, lecithin) may be added to facilitate the degradation of such microparticles.

Proteins, which are water insoluble, such as zein, can also be used as materials for the formation of drug containing microparticles. Additionally, proteins, polysaccharides and combinations thereof, which are water-soluble, can be formulated with drug into microparticles and subsequently cross-linked to form an insoluble network. For example, cyclodextrins can be complexed with individual drug molecules and subsequently cross-linked.

2. Method of making Nano-and Microparticles

Encapsulation or incorporation of drug into carrier materials to produce drug-containing microparticles can be achieved through known pharmaceutical formulation techniques. In the case of formulation in fats, waxes or wax-like materials, the carrier material is typically heated above its melting temperature and the drug is added to form a mixture comprising drug particles suspended in the carrier material, drug dissolved in the carrier material, or a mixture thereof. Microparticles can be subsequently formulated through several methods including, but not limited to, the processes of congealing, extrusion, spray chilling or aqueous dispersion. In a preferred process, wax is heated above its melting temperature, drug is added, and the molten wax-drug mixture is congealed under constant stirring as the mixture cools. Alternatively, the molten wax-drug mixture can be extruded and spheronized to form pellets or beads. These processes are known in the art.

For some carrier materials it may be desirable to use a solvent evaporation technique to produce drug-containing microparticles. In this case drug and carrier material are co-dissolved in a mutual solvent and microparticles can subsequently be produced by several techniques including, but not limited to, forming an emulsion in water or other appropriate media, spray drying or by evaporating off the solvent from the bulk solution and milling the resulting material.

In some forms, drug in a particulate form is homogeneously dispersed in a water-insoluble or slowly water soluble material. To minimize the size of the drug particles within the composition, the drug powder itself may be milled to generate fine particles prior to formulation. The process of jet milling, known in the pharmaceutical art, can be used for this purpose. In some forms, drug in a particulate form is homogeneously dispersed in a wax or wax like substance by heating the wax or wax like substance above its melting point and adding the drug particles while stirring the mixture. In this case a pharmaceutically acceptable surfactant may be added to the mixture to facilitate the dispersion of the drug particles.

The particles can also be coated with one or more modified release coatings. Solid esters of fatty acids, which are hydrolyzed by lipases, can be spray coated onto microparticles or drug particles. Zein is an example of a naturally water-insoluble protein. It can be coated onto drug containing microparticles or drug particles by spray coating or by wet granulation techniques. In addition to naturally water-insoluble materials, some substrates of digestive enzymes can be treated with cross-linking procedures, resulting in the formation of non-soluble networks. Many methods of cross-linking proteins, initiated by both chemical and physical means, have been reported. One of the most common methods to obtain cross-linking is the use of chemical cross-linking agents. Examples of chemical cross-linking agents include aldehydes (gluteraldehyde and formaldehyde) , epoxy compounds, carbodiimides, and genipin. In addition to these cross-linking agents, oxidized and native sugars have been used to cross-link gelatin. Cross-linking can also be accomplished using enzymatic means; for example, transglutaminase has been approved as a GRAS substance for cross-linking seafood products. Finally, cross-linking can be initiated by physical means such as thermal treatment, UV irradiation and gamma irradiation.

To produce a coating layer of cross-linked protein surrounding drug containing microparticles or drug particles, a water-soluble protein can be spray coated onto the microparticles and subsequently cross-linked by the one of the methods described above. Alternatively, drug-containing microparticles can be microencapsulated within protein by coacervation-phase separation (for example, by the addition of salts) and subsequently cross-linked. Some suitable proteins for this purpose include gelatin, albumin, casein, and gluten.

Polysaccharides can also be cross-linked to form a water-insoluble network. For many polysaccharides, this can be accomplished by reaction with calcium salts or multivalent cations, which cross-link the main polymer chains. Pectin, alginate, dextran, amylose and guar gum are subject to cross-linking in the presence of multivalent cations. Complexes between oppositely charged polysaccharides can also be formed; pectin and chitosan, for example, can be complexed via electrostatic interactions.

(b) Injectable/Implantable formulations

The compounds described herein can be incorporated into injectable/implantable solid or semi-solid implants, such as polymeric implants. In some forms, the compounds are incorporated into a polymer that is a liquid or paste at room temperature, but upon contact with aqueous medium, such as physiological fluids, exhibits an increase in viscosity to form a semi-solid or solid material. Exemplary polymers include, but are not limited to, hydroxyalkanoic acid polyesters derived from the copolymerization of at least one unsaturated hydroxy fatty acid copolymerized with hydroxyalkanoic acids. The polymer can be melted, mixed with the active substance and cast or injection molded into a device. Such melt fabrication requires polymers having a melting point that is below the temperature at which the substance to be delivered and polymer degrade or become reactive. The device can also be prepared by solvent casting where the polymer is dissolved in a solvent and the drug dissolved or dispersed in the polymer solution and the solvent is then evaporated. Solvent processes require that the polymer be soluble in organic solvents. Another method is compression molding of a mixed powder of the polymer and the drug or polymer particles loaded with the active agent.

Alternatively, the compounds can be incorporated into a polymer matrix and molded, compressed, or extruded into a device that is a solid at room temperature. For example, the compounds can be incorporated into a biodegradable polymer, such as polyanhydrides, polyhydroalkanoic acids (PHAs) , PLA, PGA, PLGA, polycaprolactone, polyesters, polyamides, polyorthoesters, polyphosphazenes, proteins and polysaccharides such as collagen, hyaluronic acid, albumin and gelatin, and combinations thereof and compressed into solid device, such as disks, or extruded into a device, such as rods.

The release of the one or more compounds from the implant can be varied by selection of the polymer, the molecular weight of the polymer, and/or modification of the polymer to increase degradation, such as the formation of pores and/or incorporation of hydrolyzable linkages. Methods for modifying the properties of biodegradable polymers to vary the release profile of the compounds from the implant are well known in the art.

2. Enteral Formulations

Oral formulations can include standard carriers such as pharmaceutical grades of mannitol, lactose, sodium saccharine, starch, magnesium stearate, cellulose, magnesium carbonate, etc. Such compositions will contain a therapeutically effective amount of the compound and/or antibiotic together with a suitable amount of carrier so as to provide the proper form to the patient based on the mode of administration to be used.

Suitable oral dosage forms include tablets, capsules, solutions, suspensions, syrups, and lozenges. Tablets can be made using compression or molding techniques well known in the art. Gelatin or non-gelatin capsules can prepared as hard or soft capsule shells, which can encapsulate liquid, solid, and semi-solid fill materials, using techniques well known in the art.

Formulations may be prepared using a pharmaceutically acceptable carrier. As generally used herein “carrier” includes, but is not limited to, diluents, preservatives, binders, lubricants, disintegrators, swelling agents, fillers, stabilizers, and combinations thereof.

Carrier also includes all components of the coating composition, which may include plasticizers, pigments, colorants, stabilizing agents, and glidants.

Examples of suitable coating materials include, but are not limited to, cellulose polymers such as cellulose acetate phthalate, hydroxypropyl cellulose, hydroxypropyl methylcellulose, hydroxypropyl methylcellulose phthalate and hydroxypropyl methylcellulose acetate succinate; polyvinyl acetate phthalate, acrylic acid polymers and copolymers, and methacrylic resins that are commercially available under the trade name

(Roth Pharma, Westerstadt, Germany) , zein, shellac, and polysaccharides.

Additionally, the coating material may contain conventional carriers such as plasticizers, pigments, colorants, glidants, stabilization agents, pore formers and surfactants.

“Diluents” , also referred to as "fillers, " are typically necessary to increase the bulk of a solid dosage form so that a practical size is provided for compression of tablets or formation of beads and granules. Suitable diluents include, but are not limited to, dicalcium phosphate dihydrate, calcium sulfate, lactose, sucrose, mannitol, sorbitol, cellulose, microcrystalline cellulose, kaolin, sodium chloride, dry starch, hydrolyzed starches, pregelatinized starch, silicone dioxide, titanium oxide, magnesium aluminum silicate and powdered sugar.

“Binders” are used to impart cohesive qualities to a solid dosage formulation, and thus ensure that a tablet or bead or granule remains intact after the formation of the dosage forms. Suitable binder materials include, but are not limited to, starch, pregelatinized starch, gelatin, sugars (including sucrose, glucose, dextrose, lactose and sorbitol) , polyethylene glycol, waxes, natural and synthetic gums such as acacia, tragacanth, sodium alginate, cellulose, including hydroxypropylmethylcellulose, hydroxypropylcellulose, ethylcellulose, and veegum, and synthetic polymers such as acrylic acid and methacrylic acid copolymers, methacrylic acid copolymers, methyl methacrylate copolymers, aminoalkyl methacrylate copolymers, polyacrylic acid/polymethacrylic acid and polyvinylpyrrolidone.

“Lubricants” are used to facilitate tablet manufacture. Examples of suitable lubricants include, but are not limited to, magnesium stearate, calcium stearate, stearic acid, glycerol behenate, polyethylene glycol, talc, and mineral oil.

“Disintegrants” are used to facilitate dosage form disintegration or "breakup" after administration, and generally include, but are not limited to, starch, sodium starch glycolate, sodium carboxymethyl starch, sodium carboxymethylcellulose, hydroxypropyl cellulose, pregelatinized starch, clays, cellulose, alginine, gums or cross linked polymers, such as cross-linked PVP (

XL from GAF Chemical Corp) .

“Stabilizers” are used to inhibit or retard drug decomposition reactions, which include, by way of example, oxidative reactions. Suitable stabilizers include, but are not limited to, antioxidants, butylated hydroxytoluene (BHT) ; ascorbic acid, its salts and esters; Vitamin E, tocopherol and its salts; sulfites such as sodium metabisulphite; cysteine and its derivatives; citric acid; propyl gallate, and butylated hydroxyanisole (BHA) .

(a) Controlled Release Enteral Formulations

Oral dosage forms, such as capsules, tablets, solutions, and suspensions, can for formulated for controlled release. For example, the one or more compounds and optional one or more additional active agents can be formulated into nanoparticles, microparticles, and combinations thereof, and encapsulated in a soft or hard gelatin or non-gelatin capsule or dispersed in a dispersing medium to form an oral suspension or syrup. The particles can be formed of the drug and a controlled release polymer or matrix. Alternatively, the drug particles can be coated with one or more controlled release coatings prior to incorporation in to the finished dosage form.

In another form, the one or more compounds and optional one or more additional active agents are dispersed in a matrix material, which gels or emulsifies upon contact with an aqueous medium, such as physiological fluids. In the case of gels, the matrix swells entrapping the active agents, which are released slowly over time by diffusion and/or degradation of the matrix material. Such matrices can be formulated as tablets or as fill materials for hard and soft capsules.

In still another form, the one or more compounds, and optional one or more additional active agents are formulated into a sold oral dosage form, such as a tablet or capsule, and the solid dosage form is coated with one or more controlled release coatings, such as a delayed release coatings or extended release coatings. The coating or coatings may also contain the compounds and/or additional active agents.

(1) Extended release dosage forms

The extended release formulations are generally prepared as diffusion or osmotic systems, which are known in the art. A diffusion system typically consists of two types of devices, a reservoir and a matrix, and is well known and described in the art. The matrix devices are generally prepared by compressing the drug with a slowly dissolving polymer carrier into a tablet form. The three major types of materials used in the preparation of matrix devices are insoluble plastics, hydrophilic polymers, and fatty compounds. Plastic matrices include, but are not limited to, methyl acrylate-methyl methacrylate, polyvinyl chloride, and polyethylene. Hydrophilic polymers include, but are not limited to, cellulosic polymers such as methyl and ethyl cellulose, hydroxyalkylcelluloses such as hydroxypropyl-cellulose, hydroxypropylmethylcellulose, sodium carboxymethylcellulose, and

934, polyethylene oxides and mixtures thereof. Fatty compounds include, but are not limited to, various waxes such as carnauba wax and glyceryl tristearate and wax-type substances including hydrogenated castor oil or hydrogenated vegetable oil, or mixtures thereof.

In certain preferred forms, the plastic material is a pharmaceutically acceptable acrylic polymer, including but not limited to, acrylic acid and methacrylic acid copolymers, methyl methacrylate, methyl methacrylate copolymers, ethoxyethyl methacrylates, cyanoethyl methacrylate, aminoalkyl methacrylate copolymer, poly (acrylic acid) , poly (methacrylic acid) , methacrylic acid alkylamine copolymer poly (methyl methacrylate) , poly (methacrylic acid) (anhydride) , polymethacrylate, polyacrylamide, poly (methacrylic acid anhydride) , and glycidyl methacrylate copolymers.

In certain preferred forms, the acrylic polymer is comprised of one or more ammonio methacrylate copolymers. Ammonio methacrylate copolymers are well known in the art, and are described in NF XVII as fully polymerized copolymers of acrylic and methacrylic acid esters with a low content of quaternary ammonium groups.

In one preferred form, the acrylic polymer is an acrylic resin lacquer such as that which is commercially available from Rohm Pharma under the tradename

In further preferred forms, the acrylic polymer comprises a mixture of two acrylic resin lacquers commercially available from Rohm Pharma under the tradenames

RL30D and

RS30D, respectively.

RL30D and

RS30D are copolymers of acrylic and methacrylic esters with a low content of quaternary ammonium groups, the molar ratio of ammonium groups to the remaining neutral (meth) acrylic esters being 1: 20 in

RL30D and 1: 40 in

RS30D. The mean molecular weight is about 150,000.

S-100 and

L-100 are also preferred. The code designations RL (high permeability) and RS (low permeability) refer to the permeability properties of these agents.

RL/RS mixtures are insoluble in water and in digestive fluids. However, multiparticulate systems formed to include the same are swellable and permeable in aqueous solutions and digestive fluids.

The polymers described above such as

RL/RS may be mixed together in any desired ratio in order to ultimately obtain a sustained-release formulation having a desirable dissolution profile. Desirable sustained-release multiparticulate systems may be obtained, for instance, from 100%

RL, 50%

RL and 50%

RS, and 10%

RL and 90%

RS. One skilled in the art will recognize that other acrylic polymers may also be used, such as, for example,

L.

Alternatively, extended release formulations can be prepared using osmotic systems or by applying a semi-permeable coating to the dosage form. In the latter case, the desired drug release profile can be achieved by combining low permeable and high permeable coating materials in suitable proportion.

The devices with different drug release mechanisms described above can be combined in a final dosage form comprising single or multiple units. Examples of multiple units include, but are not limited to, multilayer tablets and capsules containing tablets, beads, or granules An immediate release portion can be added to the extended release system by means of either applying an immediate release layer on top of the extended release core using a coating or compression process or in a multiple unit system such as a capsule containing extended and immediate release beads.

Extended release tablets containing hydrophilic polymers are prepared by techniques commonly known in the art such as direct compression, wet granulation, or dry granulation. Their formulations usually incorporate polymers, diluents, binders, and lubricants as well as the active pharmaceutical ingredient. The usual diluents include inert powdered substances such as starches, powdered cellulose, especially crystalline and microcrystalline cellulose, sugars such as fructose, mannitol and sucrose, grain flours and similar edible powders. Typical diluents include, for example, various types of starch, lactose, mannitol, kaolin, calcium phosphate or sulfate, inorganic salts such as sodium chloride and powdered sugar. Powdered cellulose derivatives are also useful. Typical tablet binders include substances such as starch, gelatin and sugars such as lactose, fructose, and glucose. Natural and synthetic gums, including acacia, alginates, methylcellulose, and polyvinylpyrrolidone can also be used. Polyethylene glycol, hydrophilic polymers, ethylcellulose and waxes can also serve as binders. A lubricant is necessary in a tablet formulation to prevent the tablet and punches from sticking in the die. The lubricant is chosen from such slippery solids as talc, magnesium and calcium stearate, stearic acid and hydrogenated vegetable oils.

Extended release tablets containing wax materials are generally prepared using methods known in the art such as a direct blend method, a congealing method, and an aqueous dispersion method. In the congealing method, the drug is mixed with a wax material and either spray-congealed or congealed and screened and processed.

(2) Delayed release dosage forms

Delayed release formulations can be created by coating a solid dosage form with a polymer film, which is insoluble in the acidic environment of the stomach, and soluble in the neutral environment of the small intestine.

The delayed release dosage units can be prepared, for example, by coating a drug or a drug-containing composition with a selected coating material. The drug-containing composition may be, e.g., a tablet for incorporation into a capsule, a tablet for use as an inner core in a "coated core" dosage form, or a plurality of drug-containing beads, particles or granules, for incorporation into either a tablet or capsule. Preferred coating materials include bioerodible, gradually hydrolyzable, gradually water-soluble, and/or enzymatically degradable polymers, and may be conventional "enteric" polymers. Enteric polymers, as will be appreciated by those skilled in the art, become soluble in the higher pH environment of the lower gastrointestinal tract or slowly erode as the dosage form passes through the gastrointestinal tract, while enzymatically degradable polymers are degraded by bacterial enzymes present in the lower gastrointestinal tract, particularly in the colon. Suitable coating materials for effecting delayed release include, but are not limited to, cellulosic polymers such as hydroxypropyl cellulose, hydroxyethyl cellulose, hydroxymethyl cellulose, hydroxypropyl methyl cellulose, hydroxypropyl methyl cellulose acetate succinate, hydroxypropylmethyl cellulose phthalate, methylcellulose, ethyl cellulose, cellulose acetate, cellulose acetate phthalate, cellulose acetate trimellitate and carboxymethylcellulose sodium; acrylic acid polymers and copolymers, preferably formed from acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, methyl methacrylate and/or ethyl methacrylate, and other methacrylic resins that are commercially available under the tradename

(Rohm Pharma; Westerstadt, Germany) , including

L30D-55 and L100-55 (soluble at pH 5.5 and above) ,

L-100 (soluble at pH 6.0 and above) ,

S (soluble at pH 7.0 and above, as a result of a higher degree of esterification) , and

NE, RL and RS (water-insoluble polymers having different degrees of permeability and expandability) ; vinyl polymers and copolymers such as polyvinyl pyrrolidone, vinyl acetate, vinylacetate phthalate, vinylacetate crotonic acid copolymer, and ethylene-vinyl acetate copolymer; enzymatically degradable polymers such as azo polymers, pectin, chitosan, amylose and guar gum; zein and shellac. Combinations of different coating materials may also be used. Multi-layer coatings using different polymers may also be applied.

The preferred coating weights for particular coating materials may be readily determined by those skilled in the art by evaluating individual release profiles for tablets, beads and granules prepared with different quantities of various coating materials. It is the combination of materials, method and form of application that produce the desired release characteristics, which one can determine only from the clinical studies.

The coating composition may include conventional additives, such as plasticizers, pigments, colorants, stabilizing agents, glidants, etc. A plasticizer is normally present to reduce the fragility of the coating, and will generally represent about 10 wt. %to 50 wt. %relative to the dry weight of the polymer. Examples of typical plasticizers include polyethylene glycol, propylene glycol, triacetin, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dibutyl sebacate, triethyl citrate, tributyl citrate, triethyl acetyl citrate, castor oil and acetylated monoglycerides. A stabilizing agent is preferably used to stabilize particles in the dispersion. Typical stabilizing agents are nonionic emulsifiers such as sorbitan esters, polysorbates and polyvinylpyrrolidone. Glidants are recommended to reduce sticking effects during film formation and drying, and will generally represent approximately 25 wt. %to 100 wt. %of the polymer weight in the coating solution. One effective glidant is talc. Other glidants such as magnesium stearate and glycerol monostearates may also be used. Pigments such as titanium dioxide may also be used. Small quantities of an anti-foaming agent, such as a silicone (e.g., simethicone) , may also be added to the coating composition.

IV. METHODS OF MAKING

The complexes can be synthesized using methods known in the art of metal complex synthesis such as methods that use free metals, metal salts, or other metal complexes precursors in a suitable solvent medium. Preferably, the metal complexes are synthesized starting from another metal complex precursor. As an example, the metal complex precursor – [Ir (III) (C^N) 2Cl] 2 –is mixed with excess diphosphine ligand and the mixture is refluxed in an aqueous solution of 2-ethoxyethanol overnight. The resulting iridium (III) disphosphino product is then purified using column chromatography and subsequently recrystallized in a solution of dichloromethane/diethyl ether. Specific iridium (III) diphosphino complexes are disclosed in the Examples.

V. METHODS OF USING

The compounds described herein can be administered in an effective amount to a subject that is in need of alleviation or amelioration from one or more symptoms associated with a proliferative disorder, such as cancer. The compounds are stable towards hydrolysis and in reducing conditions, such as in physiologically reducing conditions. The stability of the compounds can be determined by, for example, HPLC/MS. For example, HPLC/MS can be performed on samples (e.g., in cellulo samples) after, for example, 2 h, 10 h, 24 h, and 48 h. Visible molecular ion peaks indicate that intact compound is still present in the sample. In the experimental examples below, the compounds showed cytotoxicity against a panel of cancer cell lines. In some aspects, the compounds are luminescent. Accordingly, the compounds can be used as imaging agents.

The exact amount required will vary from subject to subject, depending on the species, age, and general condition of the subject, the severity of the disease that is being treated, the particular compound used, its mode of administration, and the like. An appropriate effective amount can be determined by one of ordinary skill in the art using only routine experimentation.

The compounds and pharmaceutical compositions described herein can be administered to the subject in a number of ways depending on whether local or systemic treatment is desired, and on the area to be treated. Thus, for example, a compound or pharmaceutical composition described herein can be administered as an ophthalmic solution and/or ointment to the surface of the eye. Moreover, a compound or pharmaceutical composition can be administered to a subject vaginally, rectally, intranasally, orally, by inhalation, or parenterally, for example, by intradermal, subcutaneous, intramuscular, intraperitoneal, intrarectal, intraarterial, intralymphatic, intravenous, intrathecal and intratracheal routes.

The condition or symptom can be a biochemical, molecular, physiological, or pathological readout. The precise dosage will vary according to a variety of factors such as subject-dependent variables (e.g., age, immune system health, etc. ) , the disease, and the treatment being effected.

The dosages or amounts of the compounds described herein are generally large enough to produce the desired effect in the method by which delivery occurs. Preferably, the dosage should not be so large as to cause adverse side effects, such as unwanted cross-reactions, anaphylactic reactions, and the like. Generally, the dosage will vary with the age, condition, sex and extent of the disease in the subject and can be determined by one of skill in the art. The dosage can be adjusted by the individual physician based on the clinical condition of the subject involved. The dose, schedule of doses and route of administration can be varied.

The compositions are administered in an effective amount and for a period of time effective to reduce one or more symptoms associated with the disease to be treated.

A. Methods of Treating Cancer

The effects of various concentrations of the diphosphino complexes on three cancer cell lines are described in the examples. All these complexes showed potent cytotoxicity towards a panel of cancer cell lines with IC ₅₀ range between 10 to 2450 nM. Successful chemotherapy relies on the strategic induction of robust apoptosis in cancer cells while sparing normal cells (CCD-19Lu) . For instance, the diphosphino complexes showed an average of about 4 to 10-fold higher selectivity over normal cells. 3 mg/kg of 8·Cl reduced tumour volume over time relative to the control group. It is noteworthy that no apparent side effects, such as weight loss, were observed and that no mice died in the 8·Cl -treated samples.

Cellular uptake of the iridium (III) diphosphine complexes showed similar uptake for both Cl and PF ₆ counter-ions except a few complexes (3, 4, 7, and 8) whose PF ₆ versions showed higher uptake. The localization of two representative complexes (1a·Cl and 8·Cl) in cancer cells was examined by confocal imaging analyses, by incubating with HeLa cancer cells pre-treated with endoplasmic reticulum (ER) , mitochondrial or lysosome specific tracker dyes, respectively. Co-localization analyses of merged luminescence images of ER-tracker together showed significant overlap indicating the localization is in the ER region. Localization of 1a·Cl and 8·Cl in ER suggests that ER stress may be involved in the cytotoxicity of these complexes. Endoplasmic reticulum is an organelle responsible for protein synthesis and folding and disruption to ER leads to stress. Due to higher protein synthesis in cancer cells ER-stress is up-regulated compared to normal cells and further aggravation by metal complexes can induce cell death. ER stress has been identified to be an important therapeutic target. Signalling pathway analysis was performed using proteomics data from MS analysis of cell lysate from HeLa cancer cells treated with 8·Cl at different time points which identified EIF2 signalling to be highly up-regulated (p-value < 10 ^-9) , in which EIF2 signalling is associated with ER-stress. Immunoblotting experiments were performed on ER stress related proteins using HeLa cancer cells treated with complexes 1a·Cl and 8·Cl, respectively (0.5 μM, 24 h) . Both complexes 1a·Cl and 8·Cl induced ER stress-related proteins such as CHOP, eIF2α-P-Ser51 and GRP78 proteins showing ER stress can be a related mechanism. In addition, both complexes 1a·Cl and 8·Cl showed significant increase in

cleaved caspase

3, 7, and 9 expressions. However, complex 8·Cl induced more significant apoptotic response upon incubation for 24 h than 1a·Cl as indicated by the presence of cleaved-PARP band for complex 8·Cl over the same period. DNA band shift was not observed for iridium complexes suggesting that the iridium complexes did not intercalate DNA.

Thus, in some embodiments a complex is administered to a subject in need thereof in an effective amount to treat cancer. For example, therapeutically effective amounts of the disclosed compounds used in the treatment of cancer will generally kill tumor cells or inhibit proliferation or metastasis of the tumor cells. Symptoms of cancer may be physical, such as tumor burden, or biological such as proliferation of cancer cells. The actual effective amounts of a compound can vary according to factors including the specific compound administered, the particular composition formulated, the mode of administration, and the age, weight, condition of the subject being treated, as well as the route of administration and the disease or disorder. In exemplary embodiments, the compounds are administered in an amount effective to kill cancer cells, improve survival of a subject with cancer, or a combination thereof.

An effective amount of the compound can be compared to a control. Suitable controls are known in the art. A typical control can be a comparison of a condition or symptom of a subject prior to and after administration of the compound, or a comparison between treatment with a compound and an art-recognized treatment for cancer such as a chemotherapeutic drug.

The data obtained from cell culture assays and animal studies, such as those disclosed herein, can be used to formulate a dosage range for use in humans. The dosage of such compounds lies preferably within a range of circulating concentrations that include the ED50 with little or no toxicity. The dosage can vary within this range depending upon the dosage form employed and the route of administration. For any compound used in the methods of the invention, the therapeutically effective dose can be estimated initially from cell culture assays. A dose can be formulated in animal models to achieve a circulating plasma concentration range that includes the IC50 (the concentration of the test compound that achieves a half-maximal inhibition of symptoms) as determined in cell culture. Such information can be used to more accurately determine useful doses in humans. Levels in plasma can be measured, for example, by high performance liquid chromatography (HPLC) . In general, the dose equivalent of a compound between about 1 ng/kg and about 100 mg/kg, inclusive, or between about 0.1 mg/kg and about 10 mg/kg, inclusive, for a typical subject.

The compositions and methods described herein are useful for treating subjects having benign or malignant tumors by delaying or inhibiting the growth of a tumor in a subject, reducing the growth or size of the tumor, inhibiting or reducing metastasis of the tumor, and/or inhibiting or reducing symptoms associated with tumor development or growth.

Malignant tumors that may be treated are classified herein according to the embryonic origin of the tissue from which the tumor is derived. Carcinomas are tumors arising from endodermal or ectodermal tissues such as skin or the epithelial lining of internal organs and glands. The disclosed compositions are particularly effective in treating carcinomas. Sarcomas, which arise less frequently, are derived from mesodermal connective tissues such as bone, fat, and cartilage. The leukemias and lymphomas are malignant tumors of hematopoietic cells of the bone marrow. Leukemias proliferate as single cells, whereas lymphomas tend to grow as tumor masses. Malignant tumors may show up at numerous organs or tissues of the body to establish a cancer.

The types of cancer that can be treated with the provided compositions and methods include, but are not limited to, cancers, such as vascular cancer such as multiple myeloma; adenocarcinomas and sarcomas of bone, bladder, brain, breast, cervical, colo-rectal, esophageal, kidney, liver, lung, nasopharangeal, pancreatic, prostate, skin, stomach, and uterine. In some embodiments, the disclosed compositions are used to treat multiple cancer types concurrently. The compositions can also be used to treat metastases or tumors at multiple locations.

B. Combination Therapies

In some embodiments, one or more of the disclosed compounds is administered in combination with one or more additional active agents. The combination therapies can include administration of the active agents together in the same admixture, or in separate admixtures. Therefore, in some embodiments, the pharmaceutical composition includes two, three, or more active agents. Such formulations typically include an effective amount of at least one of the disclosed compounds. The different active agents can have the same or different mechanisms of action.

The pharmaceutical compositions can be formulated as a pharmaceutical dosage unit, also referred to as a unit dosage form.

In some embodiments for the treatment of cancer, one or more of the disclosed compounds is used in combination with surgery, radiation therapy, immunotherapy, chemotherapy, or a combination thereof. Additional therapeutic agents include conventional cancer therapeutics such as chemotherapeutic agents, cytokines, chemokines, and radiation therapy. The majority of chemotherapeutic drugs can be divided in to: alkylating agents, antimetabolites, anthracyclines, plant alkaloids, topoisomerase inhibitors, and other antitumour agents. All of these drugs affect cell division or DNA synthesis and function in some way. Additional therapeutics include monoclonal antibodies and the new tyrosine kinase inhibitorse.g. imatinib mesylate (

or

) , which directly targets a molecular abnormality in certain types of cancer (chronic myelogenous leukemia, gastrointestinal stromal tumors) .

Representative chemotherapeutic agents include, but are not limited to cisplatin, carboplatin, oxaliplatin, mechlorethamine, cyclophosphamide, chlorambucil, vincristine, vinblastine, vinorelbine, vindesine, taxol and derivatives thereof, irinotecan, topotecan, amsacrine, etoposide, etoposide phosphate, teniposide, epipodophyllotoxins, trastuzumab

cetuximab, and rituximab (

or

) , bevacizumab

and combinations thereof.

C. Imaging

The experimental examples below show that the complexes can absorb near ultraviolet or visible radiation and emit visible light. Thus the compounds can be used for visualization, tagging, or imaging purposes. For example, in some embodiments, cells, tissue, organs or other biological or non-biological material is contacted with an effective amount of a disclosed compound to view or detect the material when it is exposed to near ultraviolet or visible radiation. In some embodiments, the material is exposed to radiation in the range of between about 250 nm and about 450 nm, inclusive, or between about 300 nm and about 380 nm, inclusive. In some embodiments, presence of the compound is a detected when it emits radiation in the range of between about 450 nm and about 700 nm, inclusive.

The compounds can be utilized in a variety of techniques, including, for example, in vitro or in vivo optical imaging. The methods can include or incorporate microscopes and imaging equipment and/or other apparatus to facilitate absorption, emission, and detection of radiation from the compounds. In some embodiments, optical imaging using the disclosed compounds is used in combination with one or more other imaging techniques, such as MRI or x- rays, to provide enhanced information for doctors monitoring complex diseases or researchers working on complex experiments.

Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilize the disclosed compounds, compositions, and methods to their fullest extent. The following examples are offered by way of illustration, not by way of limitation. While specific examples have been provided, the above description is illustrative and not restrictive. Any one or more of the features of the described forms can be combined in any manner with one or more features of any other described forms. Furthermore, many variations of the disclosed compounds, compositions, and methods will become apparent to those skilled in the art upon review of the specification.

The methods, compounds, and compositions herein described are further illustrated in the following examples, which are provided by way of illustration and are not intended to be limiting. It will be appreciated that variations in proportions and alternatives in elements of the components shown will be apparent to those skilled in the art and are within the scope of disclosed forms. Theoretical aspects are presented with the understanding that Applicants do not seek to be bound by the theory presented. All parts or amounts, unless otherwise specified, are by weight.

Examples

Example 1: Synthesis and characterization of the diphosphino iridium (III)

complexes

Materials and Methods

All chemicals were of analytical grade and purchased from Sigma-Aldrich Chemical Co. (USA) unless otherwise noted. 4-Butylphenylpyridine was prepared according to literature procedures. Reduced glutathione was obtained from Merck (Darmstadt, Germany) . Iridium trichloride (IrCl ₃) hydrate, sodium carbonate, magnesium, 1, 2-bis (diphenylphosphino) ethane nickel (II) chloride (Ni (dppe) Cl ₂) , tetrakis (triphenylphosphine) palladium (0) , aluminum chloride, acetyl chloride, ammonium hexafluorophosphate; phosphine reagents: 1, 2-bis (dicyclohexylphosphino) ethane (dcpe) , 2-bis (diphenylphosphino) ethane (dppe) , 1, 3-bis (diphenylphosphino) propane (dppp) were purchased from Sigma-Aldrich. Dichloromethane, chloroform and methanol were purchased from commercial sources and were used without further purification. Cell proliferation Kit I (MTT) was obtained from Roche (Mannheim, Germany) . Purified calf-thymus DNA (ctDNA) was purchased from Sigma-Aldrich. 123-kbp DNA ladder was obtained from Amersham Pharmacia Biotech AB (Uppsala, Sweden) . Culture medium including constituents and phosphate buffered saline solutions were purchased from Gibco BRL (Rockville, Maryland, USA) . Cell cultures flasks and 96-well microtiter plates were purchased from Nalge Nunc Int (Rochester, NY, USA) . 2-Phenyl-6- (trifluoromethyl) -benzo [d] thiazole (Hcf ₃bta) , 2-phenylbenzo [d] thiazole (Hhbta) were synthesized according to literature procedure (Park, et al., Eur. J. Org. Chem. 2012, 2012, 1984-1993. ) .

Instrumentation

All absorption spectra were recorded on a PerkinElmer Lambda 900 UV-vis spectrophotometer equipped with peltier temperature programmer PTP-6. Electrospray ionization (ESI) mass spectra were recorded on a Finnigan LCQ mass spectrometer. All NMR mass spectra were recorded on a Bruker DPX-300, -400, -500 or -600 NMR spectrometer with chemical shift (in ppm) relative to tetramethylsilane or non-deuterated solvent residual. Positive-ion fast atom bombardment (FAB) mass spectra were recorded on a Finnigan MAT95 mass spectrometer using a 3-nitrobenzyl alcohol matrix. Flow cytometry analysis was performed using a Coulter EPICS flow cytometer using a 480 long pass, 525 band pass and 625 long pass mirrors. Samples were excited with 15 mW air-cool argon convergent laser at 488 nm. Fluorescent signals were collected with Coulter Elite 4.0 software and analyzed with Winlist 1.04 and Modift 5.11 software (Verity Software House) . In MTT and protein assays, absorbance was quantified by the above spectrometer or PerkinElmer Fusion α-FP Plate Reader (Packard BioScience Company) . Proteomics studies were performed using a LTQ Orbitrap Velos mass spectrometer coupled with a Surveyor Plus 2-D HPLC system (Thermo Fishers) . The data analysis was performed using database from BIOBASE, A QIAGEN Company. Iridium content analysis was performed using Agilent 7500 ICP-MS. Elemental analyses were performed at the Institute of Chemistry of the Chinese Academy of Sciences, Beijing.

Cell line and cell culture

For biological assays, Human cervical epithelioid carcinoma (HeLa) , epithelial breast adenocarcinoma (MDA-MD-231, MCF-7) , brain glioblastoma (U87) , and normal human lung fibroblast (CCD-19Lu) cell lines were obtained commercially from ATCC (Manassas, VA, USA) .

HeLa, CCD-19Lu, MCF-7, and U87 were maintained in a minimum essential medium (MEM) with Earle’s balanced salts supplemented with 0.1 mM non-essential amino acids. MDA was maintained in Dulbecco’s modified Eagle’s medium (DMEM) with high glucose. All the media were supplemented with 10%fetal bovine serum and 2 mM of L-glutamine. Penicillin (100 U/ml) and streptomycin (100 μg/ml) were added to all media. All cultures were maintained at 37 ℃ in a 5%CO ₂ /air humidified atmosphere.

Synthesis of iridium phosphine complexes

One of the ligands –2- (4-butylphenyl) pyridine (Munoz-Rodriguez, et al., Chem. Commun. 2012, 48, 5980-5982. ) was synthesized in-house as follows: A mixture of 2-bromopyridine (0.791 g, 5.00 mmol) , (4-Butylphenyl) boronic acid (0.743g, 4.17 mmol) and Pd (PPh ₃) ₄ (pinch) as catalyst was heated at 120 ℃ for 18 h in a solvent mixture of toluene (50 ml) and an aqueous solution of K ₂CO ₃ (25 ml, 8.5 M) . After cooling to room temperature, the two layers were separated and the aqueous layer was extracted with DCM. The combined organic layers were washed with water until pH reached 7. The organic layer was then dried and the solvent evaporated. The crude was then purified by running through a silica gel column with CHCl ₃) . ¹H NMR (400 MHz, CDCl ₃) δ = 8.69 (d, J = 4.7 Hz, 1H) , 7.92 (d, J = 8.22 Hz, 2H) , 7.69 (d, J = 3.51 Hz, 2H) , 7.31 (d, J = 8.19 Hz, 2H) , 7.17 (q, J = 3.87, 4.59 Hz, 1H) , 2.67 (t, J = 7.77 Hz, 2H) , 1.65 (quintet, J = 7.59, 7.74 Hz, 2H) , 1.40 (sextet, J = 7.56, 7.47, 7.35 Hz, 2H) , 0.95 (t, J = 7.29 Hz, 3H) . ESI-MS m/z: 211.2 [M ⁺] .

(i) General procedures for the preparation of iridium (III) phosphine complexes 1-8

The corresponding dichloro-bridged iridium precursor complexes [ (C^N) ₂IrCl] ₂ were synthesized by refluxing of HC^N ligand with IrCl ₃ in aqueous solution of 2-ethoxyethanol (75%in volume) for overnight (12–18 h) ; the resulting precipitate was filtrated, washed by water, ethanol and diethyl ether and dried by air. The complexes were used without further purification.

The iridium (III) phosphine complexes (1-8) were synthesized by the following procedure with 1a·PF ₆ as an example. In a 50 ml two-neck round-bottomed flask was added [ (ppy) ₂IrCl] ₂ (100 mg, 0.093 mmol) , dppe (74.3 mg, 0.187 mmol) in methanol/CHCl ₃ (5 ml/10 ml) to give a green suspension. After heating at 80 ℃ for overnight, solvents were reduced to 1 ml and 4 ml of MeOH was added, then 200 mg of NH ₄PF ₆ was added; the resulting crude solid was added to a silica gel column and was eluted with DCM/CH ₃CN (30/1 v/v) . The fractions with greenish yellow color were collected. The organic solvent was removed under vacuum; the resulting organic residue was wetted by DCM, and 20 ml of diethylether was poured into the mixture. After filtrated and dried by air, complex 1a·PF ₆ was obtained as a yellow solid (174 mg, 0.369 mmol) .

Chloride formulations were prepared by conversion of respective PF ₆ formulation by stirring in methanol with AMBERLITE ^TM IRA410 Cl Resin for 2 h at room temperature. The solutions were filtered and solvents were evaporated in vaccum.

1a·PF ₆: [ (phenylpyridine) ₂Ir (DPPE) ] PF ₆ (Alam, et al., Polyhedron 2013, 53, 286-294) : Yield: 89%. ¹H NMR (400 MHz, DMSO-d6) δ = 7.92 (d, J = 8.2 Hz, 2H) , 7.83 (d, J = 7.8 Hz, 2H) , 7.76–7.67 (m, 6H) , 7.63 (t, J = 7.9 Hz, 2H) , 7.46 (t, J = 7.4 Hz, 2H) , 7.35 (t, J = 7.5 Hz, 4H) , 7.04 (t, J = 7.3 Hz, 4H) , 6.95 (t, J = 7.1 Hz, 2H) , 6.89 (t, J = 7.6 Hz, 4H) , 6.62 (t, J = 8.6 Hz, 4H) , 6.45 (t, J = 6.7 Hz, 2H) , 6.25–6.18 (m, 2H) , 4.06–3.79 (m, 2H) , 2.91 (d, J = 10.0 Hz, 2H) . ³¹P NMR (162 MHz, DMSO) δ = 10.80 (s) , -143.98 (hept, J = 712.7 Hz) . ¹⁹F NMR (376 MHz, DMSO) δ = -72.81 (d, J = 713.0 Hz) . ESI-MS m/z: 899.3 [M ⁺] . Anal. Calcd for C ₄₈H ₄₀F ₆IrN ₂P ₃: C 55.22, H 3.86, N 2.68. Found: C 55.60, H 4.00, N 2.8.

1a·Cl: [ (phenylpyridine) ₂Ir (DPPE) ] Cl: Yield: 82%. 1H NMR (400 MHz, MeOD) δ = 7.80 (m, 7H) , 7.46 (t, J = 7.37, 3H) , 7.35 (m, 7H) , 7.09 (m, 5H) , 6.92 (m, 6H) , 6.69 (m, 6H) , 6.40 (m, 2H) , 2.63 (m, 4H) . 31P NMR (162 MHz, MeOD) δ = 2.55 (s) , -139.99 –-148.73 (m, J = 707.6 Hz) . ESI-MS m/z: 899.3 [M+] . Anal. Calcd for C ₄₈H ₄₀IrN ₂P ₂Cl: C 52.6, H 3.61, N 2.39. Found: C 52.83, H 3.93, N 2.55.

1b·PF ₆: [ (phenylpyridine) ₂Ir (DCPE) ] PF ₆: Yield: 30%. ¹H NMR (400 MHz, CDCl ₃) δ = 9.00 (d, J = 5.8 Hz, 2H) , 8.02 (dd, J = 14.2 Hz, 7.4 Hz, 4H) , 7.59 (dd, J = 15.9 Hz, 6.9 Hz, 4H) , 6.91 (t, J = 7.3 Hz, 2H) , 6.81 (t, J = 7.3 Hz, 2H) , 6.23 (d, J = 5.0 Hz, 2H) , 3.81 (d, J = 8.6, 2H) , 2.10–1.7 (m, 23H) , 1.40–1.18 (m, 18H) , 0.99 (s, 2H) , 0.79 (d, J = 12.2 Hz, 1H) , 0.57 (s, 1H) , 0.33 (s, 1H) . ³¹P NMR (162 MHz, CDCl ₃) δ = -52.63 (s) , -144.17 (hept, J = 713.5 Hz) . ¹⁹F NMR (376 MHz, DMSO) δ = -72.69 (d, J = 713.7 Hz) . FAB-MS m/z: 923.4 [M ⁺] . Anal. Calcd for C ₄₈H ₆₄F ₆IrN ₂P ₃: C 53.97, H 6.04, N 2.62. Found: C 53.68, H 5.86, N 2.96.

1b·Cl: [ (phenylpyridine) ₂Ir (DCPE) ] Cl: Yield: 88%. ¹H NMR (400 MHz, CDCl ₃) δ = 8.81 (d, J = 5.8 Hz, 1H) , 7.96 (m, 2H) , 7.53 (m, 3H) , 7.27 (m, 1H) , 6.86 (t, J = 7.46 Hz, 1H) , 6.71 (t, J = 7.46 Hz, 1H) , 5.96 (m, 1H) , 2.21–2.79 (m, 5H) , 2.17 (s, 1H) , 1.81-1.96 (m, 6H) , 1.68-1.80 (m, 9H) , 1.60-1.68 (s, 8H) , 1.37-1.59 (m, 6H) , 1.05-1.37 (m, 11H) , 0.72-1.05 (m, 5H) , 0.36-0.51 (m, 1H) , 0.08-0.23 (m, 1H) . ³¹P NMR (162 MHz, CDCl ₃) δ = 2.61 (s) . ESI-MS m/z: 923.5 [M ⁺] . Anal. Calcd for C ₄₈H ₆₄ClIrN ₂P ₂: C 60.14, H 6.73, N 2.92. Found: C 53.68, H 5.86, N 2.96.

1c·PF ₆: [ (phenylpyridine ) ₂Ir (DPPP) ] PF ₆ (Alam, et al., Polyhedron 2013, 53, 286-294) : Yield: 89%. ¹H NMR (400 MHz, CDCl ₃) δ = 8.27 (d, J = 5.8 Hz, 2H) , 7.71 (t, J = 8.0 Hz, 2H) , 7.48 (d, J = 7.9, 2H) , 7.41 (d, J = 7.2, 2H) , 7.39–7.29 (m, 8H) , 6.98–6.88 (m, 4H) , 6.85 (d, J = 7.3 Hz, 2H) , 6.71 (t, J = 7.3 Hz, 4H) , 6.66 (d, J = 6.2 Hz, 2H) , 6.38 (t, J = 8.0 Hz, 4H) , 6.31 (d, J = 6.6 Hz, 2H) , 3.23 (s, 2H) , 3.08 (s, 2H) , 2.82–2.86 (m, 2H) . ³¹P NMR (162 MHz, CDCl ₃) δ = -30.40 (s) , -143.89 (hept, J = 711.5 Hz) . ¹⁹F NMR (376 MHz, CDCl ₃) δ = -70.11 (d, J = 711.4 Hz) . ESI-MS m/z: 913.3 [M ⁺] . Anal. Calcd for C ₄₉H ₄₂F ₆IrN ₂P ₃: C 55.63, H 4.00, N 2.65. Found: C 55.41, H 4.21, N 2.76.

1c·Cl: [ (phenylpyridine ) ₂Ir (DPPP) ] Cl: Yield: 92%. ¹H NMR (400 MHz, CDCl ₃) δ = 8.33 (d, J = 5.71 Hz, 1H) , 7.71 (t, J = 7.56 Hz, 4H) , 7.50 (t, J = 7.37, 2H) , 7.31 (m, 10H) , 6.88 (m, 4H) , 6.82 (t, J = 7.37 Hz, 2H) , 6.68 (t, J = 6.64 Hz, 2H) , 6.38 (t, J = 8.0 Hz, 4H) , 6.29 (m, 2H) , 3.43 (m, 5H) , 2.89 (m, 2H) . ³¹P NMR (162 MHz, CDCl ₃) δ = -30.89 (s) . ESI-MS m/z: 913.3 [M ⁺] . Anal. Calcd for C49H42ClIrN2P2: C 62.05, H 4.46, N 2.95. Found: C 55.41, H 4.21, N 2.76.

2·PF ₆: [ (2-phenylbenzothiazole) ₂Ir (DPPE) ] PF ₆: Yield: 82%. ¹H NMR (400 MHz, DMSO) δ = 7.91 (d, J = 7.7 Hz, 2H) , 7.68 (d, J = 8.1 Hz, 2H) , 7.56 (s, 4H) , 7.38 (t, J = 7.3 Hz, 2H) , 7.35–7.15 (m, 8H) , 7.01 (t, J = 7.5 Hz, 2H) , 6.90 (d, J = 8.5 Hz, 2H) , 6.73–6.61 (m, 12H) , 6.30 (dd, J = 7.7, 3.3 Hz, 2H) , 4.25–4.0 (m, 2H) , 3.32–3.20 (m, J = 7.9 Hz, 2H) . ³¹P NMR (162 MHz, DMSO) δ = 3.84 (s) , -143.92 (hept, J = 712.8 Hz) . ¹⁹F NMR (376 MHz, DMSO) δ = -72.93 (d, J = 706.3 Hz) . ESI-MS m/z: 1011.3 [M ⁺] . Anal. Calcd for C ₅₂H ₄₀F ₆IrN ₂P ₃S ₂: C 54.02, H 3.49, N 2.42. Found: C 53.62, H 3.67, N 2.53.

2·Cl: [ (2-phenylbenzothiazole) ₂Ir (DPPE) ] Cl: Yield: 95%. ¹H NMR (400 MHz, DMSO) δ = 7.76 (d, J = 7.75 Hz, 2H) , 7.50 (d, J = 8.0 Hz, 2H) , 7.27 (s, 4H) , 7.14 (m, 5H) , 6.90–6.96 (m, 3H) , 6.62 (m, 10H) , 6.32 (m, 2H) , 6.62 (dd, J = 9.72 Hz, 2H) , 3.26 (d, J = 8.0 Hz, 2H) , 2.17 (s, 2H) , 1.78 (s, 6H) . ³¹P NMR (162 MHz, CDCl ₃) δ = 3.89 (s) . ESI-MS m/z: 1011.3 [M ⁺] . Anal. Calcd for C52H40ClIrN2P2S2: C 59.67, H 3.85, N 2.68. Found: C 53.62, H 3.67, N 2.53.

3·PF ₆: [ (2-phenyl-6- (trifluoromethyl) benzothiazole) ₂Ir (DPPE) ] PF ₆: Yield: 81%. ¹H NMR (400 MHz, CD ₃CN) δ = 8.07 (s, 2H) , 7.99 (d, J = 7.7 Hz, 2H) , 7.57 (brs, 4H) , 7.41 (t, J = 7.3 Hz, 2H) , 7.37–7.16 (m, 6H) , 7.06 (t, J = 7.5 Hz, 2H) , 7.00 (q, J = 9.1 Hz, 4H) , 6.75 (s, 2H) , 6.70–6.53 (m, 8H) , 6.38 (d, J = 4.5 Hz, 2H) , 4.27–4.03 (m, 2H) , 3.35–3.15 (m, 2H) . ³¹P NMR (162 MHz, CD ₃CN) δ = 3.72 (s) , -143.91 (hept, J = 712.5 Hz) . ¹⁹F NMR (376 MHz, CD ₃CN) δ = -62.38 (s) , -72.93 (d, J = 706.3 Hz) . ESI-MS m/z: 1147.2 [M ⁺] . Anal. Calcd for C ₅₄H ₃₈F ₁₂IrN ₂P ₃S ₂·H ₂O: C 49.5, H 3.08, N 2.14. Found: C 49.61, H 3.01, N 2.26.

3·Cl: [ (2-phenyl-6- (trifluoromethyl) benzothiazole) ₂Ir (DPPE) ] Cl: Yield: 94%. ¹H NMR (400 MHz, CD ₃CN) δ = 7.80 (m, 3H) , 7.58 (brs, 3H) , 7.31 (t, J = 7.24 Hz, 3H) , 7.16 (t, J = 7.4 Hz, 3H) , 7.02 (m, 4H) , 6.9 (d, J = 8.85 Hz, 2H) , 6.62 (m, 8H) , 6.33 (dd, J = 3.03 Hz, 2H) , 4.76 (dd, J = 9.73 Hz, 2H) , 3.26 (d, J = 8.4 Hz, 2H) , 2.17 (s, 2H) , 1.77 (s, 3H) , 1.27 (m, 1H) . ³¹P NMR (162 MHz, CD ₃CN) δ = 3.74 (s) . ¹⁹F NMR (376 MHz, CDCl ₃) δ = -61.80 (s) . ESI-MS m/z: 1147.3 [M ⁺] . Anal. Calcd for C54H38ClF6IrN2P2S2: C 54.84, H 3.24, N 2.37. Found: C 49.61, H 3.01, N 2.26.

4·PF ₆: [ (1- (2-naphthyl) isoquinoline) ₂Ir (DPPE) ] PF ₆: Yield: 81%. ¹H NMR (400 MHz, DMSO) δ = 8.87 (s, 2H) , 8.80 (s, 2H) , 7.95 (d, J = 6.0 Hz, 4H) , 7.88 (d, J = 9.6 Hz, 4H) , 7.80–7.69 (m, 6H) , 7.42 (t, J = 7.4 Hz, 2H) , 7.33–7.27 (m, 4H) , 7.23 (t, J = 7.5 Hz, 4H) , 7.14–7.07 (m, 2H) , 7.02 (d, J = 6.6 Hz, 2H) , 6.70–6.59 (m, 10H) , 6.56 (d, J = 7.2 Hz, 2H) , 4.09–3.86 (m, 2H) , 3.05 (d, J = 9.6 Hz, 2H) . ³¹P NMR (162 MHz, CDCl ₃) δ = 12.14 (s) , -144.10 (hept, J = 710.4 Hz) . ¹⁹F NMR (376 MHz, DMSO) δ = -70.11 (d, J = 711.3 Hz) . ESI-MS m/z: 1099.4 [M ⁺] . Anal. Calcd for C ₆₄H ₄₈F ₆IrN ₂P ₃·H ₂O: C 60.90, H 3.99, N 2.22. Found: C 61.30, H 3.82, N 2.26.

4·Cl: [ (1- (2-naphthyl) isoquinoline) ₂Ir (DPPE) ] Cl: Yield: 81%. ¹H NMR (400 MHz, DMSO) δ = 8.77 (m, 2H) , 8.64 (s, 2H) , 7.76 (m, 14H) , 7.27-7.33 (m, 6H) , 7.18 (m, 6H) , 6.77 (m, 8H) , 6.58 (t, J = 6.1 Hz, 4H) , 6.49 (m, 2H) , 4.33 (dd, J = 9.79 Hz, 2H) , 3.05 (d, J = 9.9 Hz, 2H) . ³¹P NMR (162 MHz, CDCl ₃) δ = 10.44 (s) . ESI-MS m/z: 1099.5 [M ⁺] . Anal. Calcd for C64H48ClIrN2P2: C 67.74, H 4.26, N 2.47. Found: C 61.30, H 3.82, N 2.26.

5·PF ₆: [ (1- (2-thienyl) isoquinoline) ₂Ir (DPPE) ] PF ₆: Yield: 91%. ¹H NMR (400 MHz, CDCl ₃) δ = 8.62 (s, 1H) , 7.82 (s, 7H) , 7.82 (s, 6H) , 7.52 (s, 2H) , 7.42 (s, 5H) , 7.42 (s, 2H) , 6.73 (s, 1H) , 6.56 (s, 3H) , 6.56 (s, 5H) , 6.28 (s, 1H) , 6.28 (s, 1H) , 4.01 (d, J = 40.9 Hz, 6H) , 2.99 (s, 4H) . ³¹P NMR (162 MHz, CDCl ₃) δ = 18.04 (s) , -144.09 (hept, J = 710.7 Hz) . ¹⁹F NMR (376 MHz, DMSO) δ = -70.11 (d, J = 711.2 Hz) . ESI-MS m/z: 1011.3 [M ⁺] . Anal. Calcd for C ₅₂H ₄₀F ₆IrN ₂P ₃S ₂·H ₂O: C 53.19, H 3.61, N 2.39. Found: C 53.63, H 3.67, N 2.53.

5·Cl: [ (1- (2-thienyl) isoquinoline) ₂Ir (DPPE) ] Cl: Yield: 97%. ¹H NMR (400 MHz, CDCl ₃) δ = 8.70 (d, J = 8.78 Hz, 2H) , 7.78 (d, J = 8.78 Hz, 4H) , 7.67 (m, 5H) , 7.61 (m, 2H) , 7.56 (d, J = 6.59 Hz, 2H) , 7.50 (d, J = 4.86 Hz, 2H) , 7.40 (m, 3H) , 7.32 (t, J = 7.27 Hz, 5H) , 6.71 (t, J = 9.57 Hz, 4H) , 6.55 (t, J = 8.04 Hz, 4H) , 6.48 (m, 4H) , 6.38 (d, J = 4.98, 2H) , 4.30 (dd, J = 9.95 Hz, 2H) , 2.98 (d, J = 8.42 Hz, 2H) . ³¹P NMR (162 MHz, CDCl ₃) δ = 15.86 (s) . ESI-MS m/z: 1011.3 [M ⁺] . Anal. Calcd for C52H40ClIrN2P2S2: C 59.67, H 3.85, N 2.68. Found: C 53.63, H 3.67, N 2.53.

6·PF ₆: [ (2- (2-Naphthalenyl) pyridine) ₂Ir (DPPE) ] PF ₆: Yield: 90%. ¹H NMR (400 MHz, DMSO) δ = 8.50 (s, 2H) , 8.22 (d, J = 7.9, 2H) , 7.86–7.74 (m, 10H) , 7.40 (t, J = 7.3, 2H) , 7.34–7.21 (m, 10H) , 7.06 (t, J = 7.5, 2H) , 6.91 (t, J = 7.2, 4H) , 6.66 (t, J = 8.7, 4H) , 6.62–6.54 (m, 4H) , 4.06–3.85 (m, 2H) , 3.02–2.91 (m, 2H) . ³¹P NMR (162 MHz, CDCl ₃) δ = 18.04 (s) , -144.09 (hept, J = 710.7 Hz) . ³¹P NMR (162 MHz, DMSO) δ = 11.89 (s) , -135.39 –-151.37 (m, J = 710.4 Hz) . ¹⁹F NMR (376 MHz, DMSO) δ = -70.10 (d, J = 711.3 Hz) . ESI-MS m/z: 999.3 [M ⁺] . Anal. Calcd for C ₅₆H ₄₄F ₆IrN ₂P ₃: C 58.79, H 3.88, N 2.45. Found: C 58.4, H 3.87, N 2.47.

6·Cl: [ (2- (2-Naphthalenyl) pyridine) ₂Ir (DPPE) ] PF ₆: Yield: 93%. ¹H NMR (400 MHz, DMSO) δ = 8.13 (s, 2H) , 7.86 (d, J = 6.0 Hz, 4H) , 7.80 (t, J = 8.27 Hz, 4H) , 7.71 (d, J = 7.44 Hz, 2H) , 7.60 (t, J = 7.44 Hz, 2H) , 7.30 (m, 8H) , 7.20 (t, J = 7.66 Hz, 4H) , 6.98 (t, J = 7.44 Hz, 2H) , 6.89 (t, J = 7.45 Hz, 4H) , 6.78 (m, 4H) , 6.63 (d, J = 3.93 Hz, 2H) , 6.45 (t, J = 6.41 Hz, 2H) , 4.18 (dd, J = 9.93 Hz, 2H) , 2.99 (d, J = 10.14 Hz, 2H) . ³¹P NMR (162 MHz, CDCl ₃) δ = 9.22 (s) . ESI-MS m/z: 999.4 [M ⁺] . Anal. Calcd for C56H44ClIrN2P2: C 65.01, H 4.29, N 2.71. Found: C 58.4, H 3.87, N 2.47.

7·PF ₆: [ (4-methyl-2- (2-thienyl) -quinoline) ₂Ir (DPPE) ] PF ₆: Yield: 81%. ¹H NMR (400 MHz, DMSO) δ = 8.50 (s, 2H) , 8.22 (d, J = 7.9, 2H) , 7.86–7.74 (m, 10H) , 7.40 (t, J = 7.3, 2H) , 7.34–7.21 (m, 10H) , 7.06 (t, J = 7.5, 2H) , 6.91 (t, J = 7.2, 4H) , 6.66 (t, J = 8.7, 4H) , 6.62–6.54 (m, 4H) , 4.06–3.85 (m, 2H) , 3.02–2.91 (m, 2H) . ³¹P NMR (162 MHz, CDCl ₃) δ = 18.04 (s) , -144.09 (hept, J = 710.7 Hz) . ³¹P NMR (162 MHz, DMSO) δ = 11.89 (s) , -135.39 –-151.37 (m, J = 710.4 Hz) . ¹⁹F NMR (376 MHz, DMSO) δ = -70.10 (d, J = 711.3 Hz) . ESI-MS m/z: 1039.2 [M ⁺] . Anal. Calcd for C ₅₄H ₄₄F ₆IrN ₂P ₃ S ₂·H ₂O: C 53.95, H 3.86, N 2.33. Found: C 54.4, H 3.89, N 2.31.

7·Cl: [ (4-methyl-2- (2-thienyl) -quinoline) ₂Ir (DPPE) ] PF ₆: Yield: 91%. ¹H NMR (400 MHz, DMSO) δ = 7.47 (d, J = 1.31 Hz, 1H) , 7.41-7.44 (m, 5H) , 7.31 (m, 7H) , 7.18 (m, 6H) , 6.62 (t, J = 7.1 Hz, 2H) , 6.56 (t, J = 8.64, 4H) , 6.46 (m, 4H) , 7.35 (t, J = 7.1, 2H) , 5.93 (d, J = 4.87 Hz, 2H) , 4.32 (dd, J = 9.74 Hz, 2H) , 3.13 (d, J = 7.1 Hz, 2H) , 2.66 (s, 6H) . ³¹P NMR (162 MHz, CDCl ₃) δ = 2.11 (s) . ESI-MS m/z: 1039.3 [M ⁺] . Anal. Calcd for C54H44ClIrN2P2S2: C 60.35, H 4.13, N 2.61. Found: C 54.4, H 3.89, N 2.31.

8·Cl: [ (4- ⁿbutylphenylpyridine) ₂Ir (DPPE) ] Cl: Yield: 70%. ¹H NMR (400 MHz, MeOD) δ = 7.82 (m, 11H) , 7.68 (d, J = 8.3, 1H) , 7.56 (d, J = 7.5, 3H) , 7.46 (t, J = 7.73, 4H) , 7.34 (m, 4H) , 7.05 (t, J = 7.73, 2H) , 6.92 (m, 5H) , 6.74 (m, 4H) , 6.34 (m, 2H) , 6.13 (s, 2H) , 2.36 (m, 4H) , 1.39 (m, 4H) , 1.13 (m, 4H) , 0.81 (m, 6H) . ³¹P NMR (162 MHz, MeOD) δ = 12.11 (s) . ESI-MS m/z: 1011.5 [M ⁺] . Anal. Calcd for C ₅₆H ₅₆IrN ₂P ₂Cl ·4H ₂O : C 60.12, H 5.77, N 2.50. Found: C 60.12, H 5.56, N 2.4.

8·PF ₆: [ (4- ⁿbutylphenylpyridine) ₂Ir (DPPE) ] PF ₆: Yield: 65%. ¹H NMR (400 MHz, CDCl ₃) δ = 7.71 (t, J = 8.32, 5H) , 7.67 (d, J = 5.8, 2H) , 7.51 (m, 5H) , 7.41 (m, 5H) , 7.28 (m, 1H) , 6.97 (m, 2H) , 6.82 (t, J = 7.32, 4H) , 6.84 (d, J = 8.04, 2H) , 6.67 (t, J = 8.16, 4H) , 6.29 (, J = 6.24, 2H) , 6.07 (d, J = 2.68, 2H) , 3.85 (m, 2H) , 2.76 (d, J = 9.58, 2H) 2.32 (m, 4H) , 1.38 (quintet, J = 7.56, 4H) , 1.13 (m, 4H) , 0.82 (t, J = 7.40, 6H) . ³¹P NMR (162 MHz, CDCl ₃) δ = 10.61 (s) , -135.17 –-152.77 (m, J = 712.8 Hz) . ESI-MS m/z: 1011.5 [M ⁺] . Anal. Calcd for C ₅₆H ₅₆IrN ₂P ₂PF ₆: C 58.17, H 4.88, N 2.42. Found: C 58.50, H 5.11, N 2.45.

Absorption, emission, excitation, and lifetime properties of the complexes

The absorption spectra of the complexes were recorded on a Hewlett-Packard 8452A diode array spectrophotometer. All the solutions for photo-physical studies were degassed with 4-5 freeze-pump-thaw cycles on a two-compartment high vacuum line. Emission quantum yields were determined using [Ru (bpy) ₃] (PF ₆) ₂ in acetonitrile (Φ = 0.062 with excitation wavelength at 436 nm) as standard reference. Measurements were carried out on a Quanta Ray DCR-3 pulsed Nd: YAG laser system. The errors for quantum yield were estimated to be ±10%.

Stability analysis

The stability of the iridium (III) phosphine complexes was examined by UV-vis absorption spectroscopy, electrospray ionization mass spectroscopy (ESI-MS) , high performance liquid chromatography coupled mass spectrometry (LC/MS) and nuclear magnetic resonance spectroscopy (NMR) .

The UV-vis absorption-spectra and ESI-MS of complex 8 in methanol at 0 and 24 h were recorded to determine its stability in methanol. Also, the stability of

complexes

2, 3, 5, 1a·Cl, and 8 in the presence of glutathione (GSH) was examined and by monitoring the reaction of the complexes with GSH (1: 1 mol ratio) at 0 h, 24 h, and 74 h in MeOD/D ₂O (1: 9 v/v) using ¹H NMR and ESI-MS. The reactions of complex 8 with GSH (1: 100 and 1: 500 mol ratio) in Tris buffer solutions at pH 5.3 and 7.3 were further studied in detail using LC/MS after reactions for 24 h.

The stability of 8 was further examined in cell culture medium and HeLa cancer cells using LC/MS. Spectra of 8 were obtained by treating 8 (0.5 μM) with MEM medium supplemented with 10%FBS and HeLa cancer cells in MEM medium supplemented with 10%FBS (10 cm petri dish) for 2, 10, 24, and 48 h, respectively.

For the experiments with medium only, acetonitrile solution (200 μL, HPLC grade) was added to medium for extracting complex. The solution was centrifuged at 15000 rpm for 15 min at 4 ℃. The supernatant was then collected and dried. Addition of acetonitrile solution (200 μL, HPLC grade) and subsequent centrifugation at 15000 rpm for 15 min at 4 ℃ were performed. The supernatant was then subjected to LC/MS analysis.

For the HeLa cells treated with complex 8, the HeLa cells were washed with PBS (3x) followed by incubation of HeLa cells with miliQ water (500 μL) for 10 min at room temperature. An aliquot (10 μL) was removed and added to acetonitrile solution (200 μL, HPLC grade) . The solution was centrifuged at 15000 rpm for 15 min at 4 ℃. The supernatant was then collected and dried. Addition of acetonitrile solution (200 μL, HPLC grade) and subsequent centrifugation at 15000 rpm for 15 min at 4 ℃ were performed. The supernatant was then subjected to LC/MS analysis.

Cytotoxicity assay

Cytotoxicity assays of iridium (III) complexes on a panel of cancer cell lines were performed. Human cervical epithelioid carcinoma (HeLa) , epithelial breast adenocarcinoma (MDA-MD-231, MCF-7) , brain glioblastoma (U87) were used as the panel of cancer cell lines. The toxicity was measured using the MTT assay.

Cellular uptake and lipophilicity

(i) Cellular uptake

Cellular uptake of iridium complexes was determined according to literature method (Kennedy, et al., Journal of Nanobiotechnology 2014, 12) . HeLa cancer cells (6 x 10 ⁵) were seeded in 6 well plates and incubated overnight at 37 ℃ in humidified atmosphere of 5%CO ₂ and 95%air. The medium was then replaced by the medium containing iridium complexes (1 μM) . Two parallel sets of samples were prepared using medium supplemented with 10%FBS (incubated for 24 h) and serum-free medium (incubated for 2 h) , respectively. After incubation, the cells were washed with PBS (3x) . Mili-Q water (0.6 ml) was added and the plates were left on ice for 1 h. Then samples (0.3 ml) were then digested by 70%nitric acid (0.3 ml) overnight at room temperature. The solution mixtures were then subjected to inductively-coupled plasma mass spectrometry (ICP-MS) analysis.

(a) Time dependent cellular uptake of complexes 1a·Cl and 8

Similar to above, HeLa cancer cells were seeded in 6 well plates and incubated overnight at 37 ℃ in humidified atmosphere of 5%CO ₂ and 95%air. The medium was replaced by the medium containing iridium medium (1 μM) and incubated for 10 min, 30 min, 1, 2, 5, and 7 h at 37 ℃. The medium was removed and the cancer cells were washed with PBS (3x) . Mili-Q water (0.6 ml) was added and the plates were left on ice for 1 h. Then samples (0.3 mL) were then digested by 70%nitric acid (0.3 mL) overnight at room temperature. The solution mixtures were then subjected to inductively-coupled plasma mass spectrometry (ICP-MS) analysis.

(ii) Lipophilicity

An aliquot of iridium complex in DMSO (10 μL, 10 mM) was added to layered n-octanol saturated with NaCl (0.5 ml) and 0.9%NaCl in water (0.5 ml) . After several vigorous shaking the samples were incubated overnight at room temperature. 10 μl of each layer were withdrawn and diluted with mili-Q water (290 μL) . The samples were digested by 70%nitric acid (300 μL) for 24 h. The solutions were used directly for ICP-MS analysis. The logP was calculated by [Log (total amount of metal in n-octanol /total amount of metal in water) ] .

Confocal imaging

HeLa cancer cells were incubated in confocal dishes (2 x 10 ⁶) overnight at 37 ℃ in humidified atmosphere with 5%CO ₂ and 95%air in medium supplemented with 10%FBS. The medium was then replaced with

Red DND-99 (50 nM) , or ER-Tracker ^TM Red (

TR Glibenclamide) (50 nM) , or

Red CMXROS (50 nM) and incubated for 30 min at 37 ℃. The cells were then washed with medium twice. The medium was then replaced by medium containing iridium complex (1 μM) and incubated for 0.5 to 1 h at 37 ℃. The confocal images were taken on Carl Zeiss LSM 700 imaging microscope.

Immunoblotting

HeLa cancer cells were seeded in 10 cm petri dish until 90%confluency. The medium was replaced medium by containing iridium complex (0.5 μM) and the cells were incubated for 24 h at 37 ℃. The medium was removed and protein lysis buffer (500 μL) was added. The mixture was freeze and thawed for 3 times and then centrifuged at 13000 rpm at 4 ℃. The supernatant was collected and quantified by Bradford protein assay. The expressions of the following proteins were determined by immunoblotting experiments;

caspase

3, 7, 9, cleaved

caspase

3, 7, 9, PARP, cleaved-PARP, eIF2α-P-Ser51, CHOP, and GRP78.

Cell cycle analysis and apoptosis

HeLa cancer cells were seeded in 6 cm petri-dish until 70%confluency. The medium was replaced with medium containing iridium complexes (1 μM) . The cells were incubated for 6, 12, 18 and 24 h at 37 ℃. After incubation, the cells were trypsinized and dislodged. The cells were centrifuged and the supernatant was removed. The cells were then washed with PBS and centrifuged (2x) . The PBS was decanted and 70%ethanol (pre-cooled to -20 ℃; 0.5 ml) was added to the cells. The cells were shaken and then incubated at 4 ℃ for 1 h. The cells were centrifuged and the pellet was saved. The pellet was re-dissolved in 1%BSA in PBS solution (0.5 ml) and centrifuged and repeated twice. The pellet was re-dissolved in PBS solution containing RNAase (20μg/ml; 0.5 ml) and incubated at 37 ℃ for 1 h. The cells were then centrifuged and the pellet was saved. The pellet was re-dissolved in PBS solution containing propidium iodide (10 μg/ml; 1 ml) and incubated for 30 min at room temperature before analysis in Becton-Dickinson Fluorescence activated cell sorter (FACSCalibur) .

DNA gel migration assay

123 Kbp DNA ladder was incubated (Tris-HCl, 10mM, pH 8.0) with ethidium bromide or iridium complexes in a 1: 1 ratio of DNA base pair to the complex for 30 min at 37 ℃. BlueJuice ^TM gel loading buffer was added to the mixture and then allowed to undergo electrophoresis using a 2%agarose gel (w/v) and tris-acetate-EDTA (TAE) buffer. The gel was then immersed in ethidium bromide solution for 10 min, washed with water and visualized using UV trans-illuminator.

Anti-tumor activity in mice

For complex 8, the experiment involved SPF grade four-week-old female BALB/c AnN-nu mice (nude mice, 16–18 g) . The in-vivo experiment was conducted in laboratory animal unit (The University of Hong Kong) with approval from the Committee on the Use of Live Animals for Teaching and Research, The University of Hong Kong. Four million HeLa cells were inoculated into the right back flanks of female BALB/cAnN-nu (Nude) mice (7-8 weeks old) , by subcutaneous injection. When the tumor volumes reached about 100 mm ³, the mice were randomly divided into 3 treatment groups. Solvent control and complex 8 (3 mg/kg of the mice) were injected into the mice by intratumoral (3 mg/kg of the mice) , intraperitoneal (3 mg/kg of the mice) and intravenous (3 mg/kg and 5 mg/kg of the mice) 3 times per week until the mice were sacrificed. Tumor volumes were measured 3 times per week.

Iridium content in tumor, liver and plasma

Liver and tumor samples were dissected from five control and five 8-treated mice. Blood samples were collected via syringe into 20 mM EDTA solution (60 μL) . Liver and tumor samples were weighed and digested in aqua regia solution (1.5 mL) . 10 μL plasma from each sample was digested in aqua regia solution (1.5 ml) . The samples were digested for 3 days. The digested samples were then directly used for ICP-MS analysis.

Signaling pathway analysis

HeLa cancer cells were treated with 1 at 1 μM concentration for 1, 7, 24 hr at 37℃ in humidified atmosphere of 5%CO2 and 95%air. Control experiments were added equal amount of DMSO vehicle control. The cells were then washed twice with ice-cold DPBS and the cells were lysed with a urea lysis buffer (8M urea, 20mM Tris-HCl, protein phosphatase inhibitor cocktail, pH 8.0) . The cells were then scraped in 1.5ml Eppendorf tubes and spin down at 10,000 x g for 15 min at 4℃. The supernatant was saved and protein concentration was then measured. 50 μg of protein were then precipitated by adding ice-cold acetone for at least 30 min and then spin down at 13K rpm for 20 min. The supernatant was removed and pellet was air dried. The pellet was then re-suspended in 50μL buffer (8M urea in 100mM Tris, pH 8.5) . Proteins were denatured at 60℃ for 10min. DTT was added at final concentration of 5mM and incubated for 20 min at room temperature. Then iodoacetamide was added at 25mM final concentration and kept in the dark for 30 min. The mixture was diluted 4x with 100mM Tris pH 8.5 buffer to less than 1M. Trypsin was then added at 1: 100 (w: w) ratio and allowed to digest for overnight at 37℃. The mixture was then acidified with 90%formic acid (5%final concentration) and then centrifuged at 14K for 15 min. The supernatant was transferred to a new tube. The samples were desalted with StageTips (Rappsilber, Mann, Ishihama. Nat Protoc 2007, 2, 1896) before subsequent LC-MS/MS analysis.

LC-MS/MS experiments were performed on a linear ion trap Oribtrap Velos mass spectrometer (LTQ Orbitrap Velos, Thermo-Scientific) with a nanoelectrospray ion source (Shortgun Proteomics Inc. ) connected to a high performance liquid chromatography (HPLC) consisted of micoflow pumps and thermostated micro-autosampler (Finnigan, Thermo-Scientific) . The analytical column was packed in-house with a methanol -slurry of reverse-phased, fully end-capped YMC*Gel ODS-A 5 μm resin (YMC Co. Ltd., Japan) , using a pressurized “packing bomb” (Next Advance, USA) operated at 60 bar into a 10-cm fused silica capillary with emitter (75 μm I.D., 375 μm O.D.; PicoTipTM emitter, New Objective Inc., MA, USA) . Mobile phase A consisted of 0.1%formic acid in miniQ water (v/v) ; mobile phase B consisted of 0.1%formic acid in HPLC graded acetonitrile (v/v) . Three μg of desalted peptide mixture was loaded onto column by autosampler and rinsed for 6 minutes with 2%buffer B at a flow rate of ～1000 nL/min. Followed by a 100 min gradient from 2 to 30%buffer B at a flow rate of ～250 nL/min. MS analysis was performed using unattended data-dependent acquisition mode in which the mass spectrometer automatically switches between a high resolution survey scan with Oribtrap (resolution=60,000, m/z range 300 to 1,800) followed by collision-induced dissociation (CID) of the twenty most abundant ions of peptides eluting at a given time.

Peptides were identified by searching against the IPI Human database (version 3.86) using the search engine Mascot (Matrix Science) . Searches were performed with trypsin specificity (up to two missed cleavages) , with oxidation of methionine as the dynamic modification and iodoacetamide derivative of cysteine as the static modification. The mass tolerance for monoisotopic peptide identification was set to 10 ppm and 0.5 Da for fragment ions. Minimum of two peptides per protein was needed for protein identification. The final peptide false discovery rate (FDR) was < 1%, determined by using a decoy search strategy. The search results were imported into Quanty (home-written program provided by Prof. Roman Zubarev from Karolinska Institutet, Sweden) and peptides were label-free quantified using the area under chromatographic peak from extracted ion chromatograms (XICs) and protein abundances were calculated by the summation of corresponding abundances of peptides. Lists of quantified proteins were then uploaded to IPA (Qiagen) for signaling pathway analysis using default settings.

Results

Synthesized complexes

The following are a series of exemplified chemical structures of cyclometalated iridium (III) complexes containing N-heterocyclic ligands as anti-neoplastic agents.

Characterization of the complexes

The UV/Vis absorption and emission data measured in CH ₃CN at 298 K are given in Table 1 for all the complexes, and Figure 1 (for complexes 1a·Cl and 8·Cl) . These complexes show intense absorption bands at 300-380 nm with exception of complexes 5·PF ₆ and 7·PF ₆, their lowest energy absorption maxima are slightly red-shifted to ～420 nm attributable to the extended π- conjugation of and presence of thiophene unit in the C^N ligands. With reference to previous works, these absorption bands are assigned as ¹π–π*and ¹MLCT transitions.

Table 1. Photo-physical data of the iridium (III) complexes

^a In poly (methyl methacrylate) (PMMA) thin film, 2%weight sample. ^b Emission lifetime; λ _ex/nm: 501 (2·PF ₆) , 489 (3·PF ₆) , 603 (5·PF ₆) , 550 (7·PF ₆) , 485 (1a·Cl) , 489 (8·Cl) . ^c In degassed acetonitrile. n.d = not determined.

These absorptions with large absorptivity are similar to that of Ir (III) N-heterocyclic carbene (NHC) complexes (Yang et al., Chem. Sci., 2016, 7, 3123-3136, DOI: 10.1039/C5SC04458H) . Despite the similarities in absorptivity, the Ir (III) -diphosphine complexes have a larger HOMO-LUMO gap of 302.4 nm (UV-vis range) compared to Ir (III) bis-NHC complexes of 442.8 nm (visible range) . This could be attributed to the stronger electron donating property of NHC ligand compared to that of phosphine.

In general, the emission bands of Ir (III) -diphosphine complexes are vibronically structured with peak maxima in the 450-500 nm range and the emission lifetimes are in the microsecond time regime. The Ir (III) -diphosphine complexes were completely soluble in aqueous solution with addition of trace amount of dimethyl sulfoxide (DMSO) or methanol. As a representative example, the stability of complex 1a·Cl was examined. By UV-vis spectrophotometry, the absorption spectrum of 8·Cl in DMSO in the spectral region 200-400 nm revealed no observable change over a 24 h period, Figure 2.

Stability analysis

Glutathione has been shown to contribute to development of drug resistance of cisplatin and irreversible binding of glutathione to the central metal would lead to deactivation of anti-cancer metal complex in vivo. In this work, the stability of the Ir (III) -diphosphine complexes in the presence of glutathione was examined by using electro-spray ionization mass spectroscopy (ESI-MS) as well as ¹H NMR spectroscopy. Complexes 2·PF ₆, 3·PF ₆, 5·PF ₆, 7·PF ₆, 1a·Cl and 8·Cl were treated with glutathione at a 1: 1 mol ratio in CD ₃OD/D ₂O (1: 9, v/v) solution mixtures, separately and incubated. The ESI-MS spectra showed no observable change in m/z ratio. Furthermore, the ¹H NMR spectra showed no observable change in peak positions of the complexes over 72 h, Figures 3A, 3B, 3C, 3D, and 3E. These findings altogether revealed the stability of this series of Ir (III) -diphosphine complexes in the presence of glutathione. The stability of 8·Cl was further studied by liquid chromatography coupled mass spectroscopy (LC/MS) . Complex 8·Cl was treated with glutathione at 1: 100 and 1: 500 mol ratios and incubated for 24 h. The molecular peak ion corresponding to the parent ion of 8·Cl was found even after incubation for 24 h. These findings revealed that 8·Cl was stable in cancer cells for a long period of time. As 8·Cl is cytotoxic to cancer cell lines, its cytotoxicity may involve non-covalent interactions between complex cation and proteins.

Cytotoxicity assay

The cytotoxicity values of these Ir (III) -diphosphine complexes from MTT assays are tabulated in Table 2. All these complexes showed potent cytotoxicity towards a panel of cancer cell lines with IC ₅₀ range between 10 to 2450 nM. The cytotoxicity was highest in HeLa cancer cells than in breast cancer cells (MCF-7, MDA) and showed an average of about 4 to 10-fold higher selectivity over normal cells (CCD-19Lu) . The IC ₅₀ values of complexes 1a-c (·PF ₆) are in the order: DPPP > DCPE > DPPE. Complex 1a·Cl showed higher selectivity towards cancer cells than complex 8·Cl compared to normal cell line CCD-19Lu. Complexes 1a·Cl and 8·Cl were chosen as representative complexes for further biological studies.

Table 2. Cytotoxicity of iridium (III) phosphine complexes against a panel of cancer cell lines (72h, nM) ) (n. d = not determined) . HeLa (Human cervical epithelioid carcinoma) , MDA (Breast carcinoma) , MCF-7 (Human breast carcinoma) , and CCD-19Lu (Lung fibroblast) .

Time dependent cellular uptake of complexes

Time dependent flow cytometry was performed to examine 1a·Cl and 8·Cl -treated cancer cells, respectively After 18 h and 24 h the increase in sub-G1 population was more pronounced for HeLa cancer cells treated with 8·Cl than that of 1a·Cl. The time dependent cellular uptake rate of 1a·Cl (2.1 ppb /μg protein) is more than twice that of 8·Cl (0.82 ppb /μg protein) over 7 h in HeLa cancer cells (Figure 4) . Cellular uptake of the iridium (III) diphosphine complexes showed similar uptake for both Cl and PF ₆ counter-ions except complex 3, 4, 7, and 8 whose PF ₆ versions showed higher uptake. In previous works iridium (III) bis-NHC complexes have been reported to localize in the endoplasmic reticulum and mitochondria (Yang et al., Chem. Sci., 2016, 7, 3123-3136, DOI: 10.1039/C5SC04458H; Zhong et al., Chemical Science, 2015, 6, 5400-5408) . In this work, the localization of 1a·Cl and 8·Cl in cancer cells was examined by confocal imaging analyses. Complex 1a·Cl and 8·Cl were incubated with HeLa cancer cells (1 μM, 0.5 h, 37 ℃) pre-treated with endoplasmic reticulum (ER) , mitochondrial or lysosome specific tracker dyes, respectively Co-localization analyses of merged luminescence images of ER-tracker together with 1a·Cl and 8·Cl show significant overlap indicating the localization is in the ER region. No change in localization after a period of 1 h was observed. The localization between Ir (III) bis-NHC and -diphosphine complexes are similar in cancer cells despite the different ancillary ligands. Localization of 1a·Cl and 8·Cl in ER suggests that ER stress may be involved in the cytotoxicity of these complexes. Endoplasmic reticulum is an organelle responsible for protein synthesis and folding and disruption to ER leads to stress. Due to higher protein synthesis in cancer cells ER-stress is up-regulated compared to normal cells and further aggravation by metal complexes will induce cell death. ER stress has been identified to be an important therapeutic target. Signalling pathway analysis was performed using proteomics data from MS analysis of cell lysate from HeLa cancer cells treated with 8·Cl at different time points which identified EIF2 signalling to be highly up-regulated (p-value < 10 ^-9) , in which EIF2 signalling is associated with ER-stress. Immunoblotting experiments were performed on ER stress related proteins using HeLa cancer cells treated with complexes 1a·Cl and 8·Cl, respectively (0.5 μM, 24 h) . ER-stress related proteins include CCAAT-enhancer-binding protein homologous protein (CHOP) which is an ER-stress inducible protein which mediates apoptosis, eIF2α-P-Ser51 represses protein synthesis during ER stress (Teske et al., Mol. Biol. Cell November 15, 2011, vol. 22, no. 22, 4390-4405) and GRP78 an important ER chaperone protein which regulates protein quality control (Wang et al., Antioxid Redox Signal. 2009 Sep; 11 (9) : 2307–2316, doi: 10.1089/ars. 2009.2485) . Both complexes 1a·Cl and 8·Cl induced CHOP, eIF2α-P-Ser51 and GRP78 proteins confirming ER stress related mechanism. In addition, both complexes 1a·Cl and 8·Cl showed significant increase in

cleaved caspase

In vivo inhibitory properties of the Ir (III) complexes

The in vivo tumor-inhibiting properties of a few Ir (III) complexes have been reported to date (Zhong et al., Chemical Science, 2015, 6, 5400-5408; Song et al., J. Med. Chem 2013, 56, 6531-6535; Ma et al., Angew. Chem. Int. Ed., 2014, 53, 9178-9182) . Most of the reported complexes showed tumour inhibition at high concentrations or after extension of treatment time. Complex 8·Cl was investigated to see if it could inhibit growth of cervical cancer in nude mice. A xenograft model in nude mice containing tumours by inoculating with HeLa cancer cells was used. Complex 8·Cl (3 mg/kg) was given via intratumoral (2 mg/kg) , intraperitoneal (3 mg/kg) and intravenous injections (3 and 5 mg/kg) . Figure 5A shows the changes in tumour volume after treatment with 8·Cl intraperitoneal injections. After 13-days treatment, tumour volume of the 8·Cl -treated group decreased by 54.7%relative to the control group. It is noteworthy that no apparent side effects, such as weight loss, were observed and that no mice died in the 8·Cl -treated samples, Figure 5B. At the end of the experiment mice were sacrificed and the iridium localization in tumour, liver and plasma was determined by inductively coupled plasma mass spectrometry (ICP-MS) . The iridium metal content was found in the tumor samples, Table 3.

Table 3. Iridium content in various nude mice tissues (liver, tumor, plasma) treated with 8·Cl. ^a

^a –Measured by ICP-MS. Data are shown as mean ± SEM.

Figure 5C shows the changes in tumour volume after treatment with 8·Cl via intratumoral injections. After 12-days treatment, tumour volume of the 8·Cl -treated group decreased by 52.9%relative to the control group. It is noteworthy that no apparent side effects, such as weight loss, were observed and that no mice died in the 8·Cl -treated samples, Figure 5D. Figure 5E shows the changes in tumour volume after treatment with 8·Cl via intravenous injections. After 16-days treatment, tumour volume of the 8·Cl -treated group decreased by 90.2% (3 mg/kg) and 78.5% (5 mg/kg) relative to the control group. It is noteworthy that no apparent side effects, such as weight loss, were observed and that no mice died in the 8·Cl -treated samples, Figure 5F.

In summary, luminescent cyclometalated Ir (III) -diphosphine complexes showed favourable luminescent properties. Importantly, they were stable against glutathione and even stable in cancer cells over a long period. They were highly cytotoxic against a panel of cancer cell lines. Periphery groups on the ligands showed significant impact on cellular uptake rate. Complex 8·Cl displayed significant reduction in tumour volume in vivo which suggest that this series of iridium (III) diphosphine complexes would be a promising class of complexes for anti-neoplastic therapy.

Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of skill in the art to which the disclosed invention belongs. Publications cited herein and the materials for which they are cited are specifically incorporated by reference.

Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims.

Claims

A compound having the formula:

wherein:

r is an integer between 0 and 5, inclusive;

q is an integer between 1 and 6, inclusive;

M is a transition metal;

the oxidation state of M is between +1 and +7, inclusive;

R ₁’, R ₂’, R ₃’, R ₄’, R ₅’, R ₆’, R ₇’, and R ₈’ are independently hydrogen, substituted aryl, unsubstituted aryl, substituted heteroaryl, unsubstituted heteroaryl, substituted C ₃-C ₂₀ cycloalkyl, unsubstituted C ₃-C ₂₀ cycloalkyl, substituted polyaryl, unsubstituted polyaryl, substituted polyheteroaryl, unsubstituted polyheteroaryl, substituted C ₃-C ₂₀ heterocyclyl, unsubstituted C ₃-C ₂₀ heterocyclyl, substituted C ₃-C ₂₀ cycloalkenyl, unsubstituted C ₃-C ₂₀ cycloalkenyl, substituted C ₃-C ₂₀ cycloalkynyl, unsubstituted C ₃-C ₂₀ cycloalkynyl, substituted alkyl, unsubstituted alkyl, substituted alkenyl, unsubstituted alkenyl, substituted alkynyl, unsubstituted alkynyl, substituted alkoxy, unsubstituted alkoxy, substituted aroxy, unsubstituted aroxy, substituted alkylthio, unsubstituted alkylthio, substituted arylthio, unsubstituted arylthio, substituted carbonyl, unsubstituted carbonyl, substituted carboxyl, unsubstituted carboxyl, substituted amino, unsubstituted amino, substituted amido, unsubstituted amido, substituted sulfonyl, unsubstituted sulfonyl, substituted sulfonic acid, unsubstituted sulfonic acid, substituted phosphoryl, unsubstituted phosphoryl, substituted phosphonyl, unsubstituted phosphonyl, halogen, cyano, or hydroxyl;

A’ is a bond, absent, substituted aryl, unsubstituted aryl, substituted heteroaryl, unsubstituted heteroaryl, substituted C ₃-C ₂₀ cycloalkyl, unsubstituted C ₃-C ₂₀ cycloalkyl, substituted polyaryl, unsubstituted polyaryl, substituted polyheteroaryl, unsubstituted polyheteroaryl, substituted C ₃-C ₂₀ heterocyclyl, unsubstituted C ₃-C ₂₀ heterocyclyl, substituted C ₃-C ₂₀ cycloalkenyl, unsubstituted C ₃-C ₂₀ cycloalkenyl, substituted C ₃-C ₂₀ cycloalkynyl, unsubstituted C ₃-C ₂₀ cycloalkynyl, substituted alkyl, unsubstituted alkyl, substituted alkenyl, unsubstituted alkenyl, substituted alkynyl, unsubstituted alkynyl, substituted alkoxy, unsubstituted alkoxy, substituted aroxy, unsubstituted aroxy, substituted alkylthio, unsubstituted alkylthio, substituted arylthio, unsubstituted arylthio, substituted carbonyl, unsubstituted carbonyl, substituted carboxyl, unsubstituted carboxyl, substituted amino, unsubstituted amino, substituted amido, unsubstituted amido, substituted sulfonyl, unsubstituted sulfonyl, substituted sulfonic acid, unsubstituted sulfonic acid, substituted phosphoryl, unsubstituted phosphoryl, substituted phosphonyl, or unsubstituted phosphonyl;

optionally, R ₃’ and R ₄’ together form R ₉’, wherein,

R ₉’ is unsubstituted alkylene, substituted alkylene, unsubstituted alkyl, substituted alkyl, substituted aryl, unsubstituted aryl, substituted heteroaryl, unsubstituted heteroaryl, substituted C ₃-C ₂₀ cycloalkyl, unsubstituted C ₃-C ₂₀ cycloalkyl, substituted polyaryl, unsubstituted polyaryl, substituted polyheteroaryl, unsubstituted polyheteroaryl, substituted C ₃-C ₂₀ heterocyclyl, unsubstituted C ₃-C ₂₀ heterocyclyl, substituted C ₃-C ₂₀ cycloalkenyl, unsubstituted C ₃-C ₂₀ cycloalkenyl, substituted C ₃-C ₂₀ cycloalkynyl, unsubstituted C ₃-C ₂₀ cycloalkynyl, substituted alkenyl, unsubstituted alkenyl, substituted alkynyl, unsubstituted alkynyl, substituted alkoxy, unsubstituted alkoxy, substituted aroxy, unsubstituted aroxy, substituted alkylthio, unsubstituted alkylthio, substituted arylthio, unsubstituted arylthio, substituted carbonyl, unsubstituted carbonyl, substituted carboxyl, unsubstituted carboxyl, substituted amino, unsubstituted amino, substituted amido, unsubstituted amido, substituted sulfonyl, unsubstituted sulfonyl, substituted sulfonic acid, unsubstituted sulfonic acid, substituted phosphoryl, unsubstituted phosphoryl, substituted phosphonyl, or unsubstituted phosphonyl; and

wherein:

(i) when M is iridium and P (R ₁’R ₂’R ₃’) and P (R ₄’R ₅’R ₆’) together form 1, 2-bis (diphenylphosphino) ethane, R ₇’-A’-R ₈’ is not 2- (2, 4-difluorophenyl) pyridine or 2-phenylpyridine;

(ii) when M is iridium and P (R ₁’R ₂’R ₃’) and P (R ₄’R ₅’R ₆’) together form 1, 3-bis (diphenylphosphino) propane, R ₇’-A’-R ₈’ is not 2-phenylpyridine;

(iii) when M is iridium, R ₁’, R ₂’, R ₅’, and R ₆’ are p-tolyl, and R ₃’ and R ₄’ together form 1, 1’-binaphthalene, R ₇’-A’-R ₈’ is not 2- (2, 4-difluorophenyl) pyridine;

(iv) when M is iridium and P (R ₁’R ₂’R ₃’) and P (R ₄’R ₅’R ₆’) together form 1, 2-bis (diphenylphosphino) methane, R ₇’-A’-R ₈’ is not 2- (2, 4-difluorophenyl) -4-fluoropyridine;

(v) when M is iridium, R ₁’, R ₂’, R ₅’, and R ₆’ are phenyl, and R ₃’ and R ₄’ together form benzene, ethene, or dimethyldiphenyl silane, R ₇’-A’-R ₈’ is not halogen-substituted 2-phenylpyridine or fluorosubstituted 2-phenylpyridine; and

(vi) when M is iridium and R ₁’, R ₂’, R ₃’, R ₄’, R ₅’, and R ₆’ are alkoxy, C ₁-C ₅ alkoxy, or ethoxy, R ₇’-A’-R ₈’ is not halogen-substituted 2-phenylpyridine or fluorosubstituted 2-phenylpyridine.
The compound of claim 1, wherein M is selected from the group consisting of iridium, rhodium, cobalt, iron, ruthenium, osmium, nickel, palladium, platinum, manganese, technetium, rhenium, chromium, molybdenum, tungsten, vanadium, niobium, tantalum, titanium, zirconium, hafnium, scandium, yttrium, copper, silver, gold, and zinc.
The compound of claim 1 or 2, wherein R ₇’, and R ₈’ are independently substituted aryl, unsubstituted aryl, substituted heteroaryl, unsubstituted heteroaryl, substituted C ₃-C ₂₀ cycloalkyl, unsubstituted C ₃-C ₂₀ cycloalkyl, substituted polyaryl, unsubstituted polyaryl, substituted polyheteroaryl, unsubstituted polyheteroaryl, substituted C ₃-C ₂₀ heterocyclyl, unsubstituted C ₃-C ₂₀ heterocyclyl, substituted C ₃-C ₂₀ cycloalkenyl, unsubstituted C ₃-C ₂₀ cycloalkenyl, substituted C ₃-C ₂₀ cycloalkynyl, unsubstituted C ₃-C ₂₀ cycloalkynyl, substituted alkyl, unsubstituted alkyl, substituted alkenyl, unsubstituted alkenyl, substituted alkynyl, unsubstituted alkynyl, substituted alkoxy, unsubstituted alkoxy, substituted aroxy, unsubstituted aroxy, substituted alkylthio, unsubstituted alkylthio, substituted arylthio, unsubstituted arylthio, substituted carbonyl, unsubstituted carbonyl, substituted carboxyl, unsubstituted carboxyl, substituted amino, unsubstituted amino, substituted amido, unsubstituted amido, substituted sulfonyl, unsubstituted sulfonyl, substituted sulfonic acid, unsubstituted sulfonic acid, substituted phosphoryl, unsubstituted phosphoryl, substituted phosphonyl, unsubstituted phosphonyl, halogen, cyano, or hydroxyl.
The compound of any one of claims 1-3, wherein R ₃’ and R ₄’ together form R ₉’, wherein R ₉’ is unsubstituted alkylene, substituted alkylene, unsubstituted alkyl, substituted alkyl, substituted aryl, unsubstituted aryl, substituted heteroaryl, unsubstituted heteroaryl, substituted C ₃-C ₂₀ cycloalkyl, unsubstituted C ₃-C ₂₀ cycloalkyl, substituted polyaryl, unsubstituted polyaryl, substituted polyheteroaryl, unsubstituted polyheteroaryl, substituted C ₃-C ₂₀ heterocyclyl, unsubstituted C ₃-C ₂₀ heterocyclyl, substituted C ₃-C ₂₀ cycloalkenyl, unsubstituted C ₃-C ₂₀ cycloalkenyl, substituted C ₃-C ₂₀ cycloalkynyl, unsubstituted C ₃-C ₂₀ cycloalkynyl, substituted alkenyl, unsubstituted alkenyl, substituted alkynyl, or unsubstituted alkynyl.
The compound of any one of claims 1-4, wherein:

A’ is a single bond; and

R ₁’, R ₂’, R ₃’, R ₄’, R ₅’, R ₆’, R ₇’, and R ₈’ are independently substituted aryl, unsubstituted aryl, substituted heteroaryl, unsubstituted heteroaryl, substituted C ₃-C ₂₀ cycloalkyl, unsubstituted C ₃-C ₂₀ cycloalkyl, substituted polyaryl, unsubstituted polyaryl, substituted polyheteroaryl, unsubstituted polyheteroaryl, substituted C ₃-C ₂₀ heterocyclyl, unsubstituted C ₃-C ₂₀ heterocyclyl, substituted C ₃-C ₂₀ cycloalkenyl, unsubstituted C ₃-C ₂₀ cycloalkenyl, substituted C ₃-C ₂₀ cycloalkynyl, or unsubstituted C ₃-C ₂₀ cycloalkynyl.
The compound of any one of claims 1-5, wherein R ₇’, and R ₈’ are independently aryl, unsubstituted aryl, substituted heteroaryl, unsubstituted heteroaryl, substituted polyaryl, unsubstituted polyaryl, substituted polyheteroaryl, or unsubstituted polyheteroaryl.
The compound of any one of claims 1-6, wherein M is iridium and the oxidation state of iridium is +3, wherein the compound further comprises a counter-ion.
The compound of any one of claims 1-7, wherein q is 1, and r is 2.
The compound of any one of claims 1-8, wherein R ₉’ is unsubstituted C ₁-C ₆ alkylene or substituted C ₁-C ₆ alkylene.
The compound of any one of claims 1-9, wherein each R ₇’ is independently an unsubstituted heteroaryl, substituted heteroaryl, unsubstituted polyheteroaryl, or substituted polyheteroaryl, wherein the unsubstituted heteroaryl, substituted heteroaryl, unsubstituted polyheteroaryl, or substituted polyheteroaryl comprise one or more nitrogen atoms;

wherein each R ₈’, is independently an unsubstituted aryl, substituted aryl, unsubstituted polyaryl, or substituted polyaryl; and

wherein R ₁’, R ₂’, R ₅’, and R ₆’ are independently an unsubstituted aryl, substituted aryl, unsubstituted polyaryl, substituted polyaryl, independently a substituted C ₃-C ₂₀ cycloalkyl, unsubstituted C ₃-C ₂₀ cycloalkyl, substituted C ₃-C ₂₀ heterocyclyl, unsubstituted C ₃-C ₂₀ heterocyclyl, substituted C ₃-C ₂₀ cycloalkenyl, unsubstituted C ₃-C ₂₀ cycloalkenyl, substituted C ₃-C ₂₀ cycloalkynyl, or unsubstituted C ₃-C ₂₀ cycloalkynyl.
The compound of any one of claims 7-10, having the formula:

wherein:

R ₁-R ₃₆ are independently hydrogen, substituted aryl, unsubstituted aryl, substituted heteroaryl, unsubstituted heteroaryl, substituted C ₃-C ₂₀ cycloalkyl, unsubstituted C ₃-C ₂₀ cycloalkyl, substituted polyaryl, unsubstituted polyaryl, substituted polyheteroaryl, unsubstituted polyheteroaryl, substituted C ₃-C ₂₀ heterocyclyl, unsubstituted C ₃-C ₂₀ heterocyclyl, substituted C ₃-C ₂₀ cycloalkenyl, unsubstituted C ₃-C ₂₀ cycloalkenyl, substituted C ₃-C ₂₀ cycloalkynyl, unsubstituted C ₃-C ₂₀ cycloalkynyl, substituted alkyl, unsubstituted alkyl, substituted alkenyl, unsubstituted alkenyl, substituted alkynyl, unsubstituted alkynyl, substituted alkoxy, unsubstituted alkoxy, substituted aroxy, unsubstituted aroxy, substituted alkylthio, unsubstituted alkylthio, substituted arylthio, unsubstituted arylthio, substituted carbonyl, unsubstituted carbonyl, substituted carboxyl, unsubstituted carboxyl, substituted amino, unsubstituted amino, substituted amido, unsubstituted amido, substituted sulfonyl, unsubstituted sulfonyl, substituted sulfonic acid, unsubstituted sulfonic acid, substituted phosphoryl, unsubstituted phosphoryl, substituted phosphonyl, unsubstituted phosphonyl, halogen, cyano, or hydroxyl;

R ₃₇ is R ₉’;

n is +1;

A is the counter-ion;

b is -1; and

y is 1.
The compound of claim 11, wherein:

R ₁-R ₃₆ are independently substituted alkyl, unsubstituted alkyl, or hydrogen.
The compound of claim 12, wherein:

R ₁-R ₃₆ are each hydrogen; and

A is Cl, PF ₆, OTf, or a pharmaceutically acceptable anion.
The compound of claim 11, wherein for Formula II, R ₇ and R ₁₅ are independently C ₁-C ₄ substituted alkyl or unsubstituted alkyl.
The compound of any one of claims 7-10, having the formula:

wherein:

R ₁-R ₅₆ are independently hydrogen, substituted aryl, unsubstituted aryl, substituted heteroaryl, unsubstituted heteroaryl, substituted C ₃-C ₂₀ cycloalkyl, unsubstituted C ₃-C ₂₀ cycloalkyl, substituted polyaryl, unsubstituted polyaryl, substituted polyheteroaryl, unsubstituted polyheteroaryl, substituted C ₃-C ₂₀ heterocyclyl, unsubstituted C ₃-C ₂₀ heterocyclyl, substituted C ₃-C ₂₀ cycloalkenyl, unsubstituted C ₃-C ₂₀ cycloalkenyl, substituted C ₃-C ₂₀ cycloalkynyl, unsubstituted C ₃-C ₂₀ cycloalkynyl, substituted alkyl, unsubstituted alkyl, substituted alkenyl, unsubstituted alkenyl, substituted alkynyl, unsubstituted alkynyl, substituted alkoxy, unsubstituted alkoxy, substituted aroxy, unsubstituted aroxy, substituted alkylthio, unsubstituted alkylthio, substituted arylthio, unsubstituted arylthio, substituted carbonyl, unsubstituted carbonyl, substituted carboxyl, unsubstituted carboxyl, substituted amino, unsubstituted amino, substituted amido, unsubstituted amido, substituted sulfonyl, unsubstituted sulfonyl, substituted sulfonic acid, unsubstituted sulfonic acid, substituted phosphoryl, unsubstituted phosphoryl, substituted phosphonyl, unsubstituted phosphonyl, halogen, cyano, or hydroxyl;

R ₅₇ is R ₉’;

n is +1;

A is the counter-ion;

b is -1; and

y is 1.
The compound of claim 15, wherein:

R ₁-R ₅₆ are independently substituted alkyl, unsubstituted alkyl, or hydrogen.
The compound of claim 16, wherein:

R ₁-R ₅₆ are each hydrogen; and

A is Cl, PF ₆, OTf, or a pharmaceutically acceptable anion.
The compound of any one of claims 7-10, having the formula:

wherein:

R ₁-R ₅₄ are independently hydrogen, substituted aryl, unsubstituted aryl, substituted heteroaryl, unsubstituted heteroaryl, substituted C ₃-C ₂₀ cycloalkyl, unsubstituted C ₃-C ₂₀ cycloalkyl, substituted polyaryl, unsubstituted polyaryl, substituted polyheteroaryl, unsubstituted polyheteroaryl, substituted C ₃-C ₂₀ heterocyclyl, unsubstituted C ₃-C ₂₀ heterocyclyl, substituted C ₃-C ₂₀ cycloalkenyl, unsubstituted C ₃-C ₂₀ cycloalkenyl, substituted C ₃-C ₂₀ cycloalkynyl, unsubstituted C ₃-C ₂₀ cycloalkynyl, substituted alkyl, unsubstituted alkyl, substituted alkenyl, unsubstituted alkenyl, substituted alkynyl, unsubstituted alkynyl, substituted alkoxy, unsubstituted alkoxy, substituted aroxy, unsubstituted aroxy, substituted alkylthio, unsubstituted alkylthio, substituted arylthio, unsubstituted arylthio, substituted carbonyl, unsubstituted carbonyl, substituted carboxyl, unsubstituted carboxyl, substituted amino, unsubstituted amino, substituted amido, unsubstituted amido, substituted sulfonyl, unsubstituted sulfonyl, substituted sulfonic acid, unsubstituted sulfonic acid, substituted phosphoryl, unsubstituted phosphoryl, substituted phosphonyl, unsubstituted phosphonyl, halogen, cyano, or hydroxyl;

R ₄₅ is R ₉’;

n is +1;

A is the counter-ion;

b is -1; and

y is 1.
The compound of claim 8, wherein:

R ₁-R ₄₄ are independently substituted alkyl, unsubstituted alkyl, or hydrogen.
The compound of claim 19, wherein:

R ₁-R ₄₄ are each hydrogen; and

A is Cl, PF ₆, OTf, or a pharmaceutically acceptable anion.
The compound of any one of claims 7-10, having the formula:

wherein:

R ₁-R ₄₀ are independently hydrogen, substituted aryl, unsubstituted aryl, substituted heteroaryl, unsubstituted heteroaryl, substituted C ₃-C ₂₀ cycloalkyl, unsubstituted C ₃-C ₂₀ cycloalkyl, substituted polyaryl, unsubstituted polyaryl, substituted polyheteroaryl, unsubstituted polyheteroaryl, substituted C ₃-C ₂₀ heterocyclyl, unsubstituted C ₃-C ₂₀ heterocyclyl, substituted C ₃-C ₂₀ cycloalkenyl, unsubstituted C ₃-C ₂₀ cycloalkenyl, substituted C ₃-C ₂₀ cycloalkynyl, unsubstituted C ₃-C ₂₀ cycloalkynyl, substituted alkyl, unsubstituted alkyl, substituted alkenyl, unsubstituted alkenyl, substituted alkynyl, unsubstituted alkynyl, substituted alkoxy, unsubstituted alkoxy, substituted aroxy, unsubstituted aroxy, substituted alkylthio, unsubstituted alkylthio, substituted arylthio, unsubstituted arylthio, substituted carbonyl, unsubstituted carbonyl, substituted carboxyl, unsubstituted carboxyl, substituted amino, unsubstituted amino, substituted amido, unsubstituted amido, substituted sulfonyl, unsubstituted sulfonyl, substituted sulfonic acid, unsubstituted sulfonic acid, substituted phosphoryl, unsubstituted phosphoryl, substituted phosphonyl, unsubstituted phosphonyl, halogen, cyano, or hydroxyl;

R ₄₁ is R ₉’;

n is +1;

A is the counter-ion;

b is -1; and

y is 1.
The compound of claim 21, wherein:

R ₁-R ₄₀ are independently substituted alkyl, unsubstituted alkyl, or hydrogen.
The compound of claim 22, wherein:

R ₁-R ₄₀ are each hydrogen; and

A is Cl, PF ₆, OTf, or a pharmaceutically acceptable anion.
The compound of any one of claims 7-10, having the formula:

wherein:

R ₁-R ₃₄ are independently hydrogen, substituted aryl, unsubstituted aryl, substituted heteroaryl, unsubstituted heteroaryl, substituted C ₃-C ₂₀ cycloalkyl, unsubstituted C ₃-C ₂₀ cycloalkyl, substituted polyaryl, unsubstituted polyaryl, substituted polyheteroaryl, unsubstituted polyheteroaryl, substituted C ₃-C ₂₀ heterocyclyl, unsubstituted C ₃-C ₂₀ heterocyclyl, substituted C ₃-C ₂₀ cycloalkenyl, unsubstituted C ₃-C ₂₀ cycloalkenyl, substituted C ₃-C ₂₀ cycloalkynyl, unsubstituted C ₃-C ₂₀ cycloalkynyl, substituted alkyl, unsubstituted alkyl, substituted alkenyl, unsubstituted alkenyl, substituted alkynyl, unsubstituted alkynyl, substituted alkoxy, unsubstituted alkoxy, substituted aroxy, unsubstituted aroxy, substituted alkylthio, unsubstituted alkylthio, substituted arylthio, unsubstituted arylthio, substituted carbonyl, unsubstituted carbonyl, substituted carboxyl, unsubstituted carboxyl, substituted amino, unsubstituted amino, substituted amido, unsubstituted amido, substituted sulfonyl, unsubstituted sulfonyl, substituted sulfonic acid, unsubstituted sulfonic acid, substituted phosphoryl, unsubstituted phosphoryl, substituted phosphonyl, unsubstituted phosphonyl, halogen, cyano, or hydroxyl;

R ₃₅ is R ₉’;

n is +1;

A is the counter-ion;

b is -1; and

y is 1.
The compound of claim 24, wherein:

R ₁-R ₃₄ are independently substituted alkyl, unsubstituted alkyl, or hydrogen.
The compound of claim 25, wherein:

R ₁-R ₃₄ are each hydrogen; and

A is Cl, PF ₆, OTf, or a pharmaceutically acceptable anion.
A pharmaceutical composition comprising a compound having the formula:

in an effective amount to inhibit growth of cancer cells,

wherein:

r is an integer between 0 and 5, inclusive;

q is an integer between 1 and 6, inclusive;

M is a transition metal;

the oxidation state of M is between +1 and +7, inclusive;

R ₁’, R ₂’, R ₃’, R ₄’, R ₅’, R ₆’, R ₇’, and R ₈’ are independently hydrogen, substituted aryl, unsubstituted aryl, substituted heteroaryl, unsubstituted heteroaryl, substituted C ₃-C ₂₀ cycloalkyl, unsubstituted C ₃-C ₂₀ cycloalkyl, substituted polyaryl, unsubstituted polyaryl, substituted polyheteroaryl, unsubstituted polyheteroaryl, substituted C ₃-C ₂₀ heterocyclyl, unsubstituted C ₃-C ₂₀ heterocyclyl, substituted C ₃-C ₂₀ cycloalkenyl, unsubstituted C ₃-C ₂₀ cycloalkenyl, substituted C ₃-C ₂₀ cycloalkynyl, unsubstituted C ₃-C ₂₀ cycloalkynyl, substituted alkyl, unsubstituted alkyl, substituted alkenyl, unsubstituted alkenyl, substituted alkynyl, unsubstituted alkynyl, substituted alkoxy, unsubstituted alkoxy, substituted aroxy, unsubstituted aroxy, substituted alkylthio, unsubstituted alkylthio, substituted arylthio, unsubstituted arylthio, substituted carbonyl, unsubstituted carbonyl, substituted carboxyl, unsubstituted carboxyl, substituted amino, unsubstituted amino, substituted amido, unsubstituted amido, substituted sulfonyl, unsubstituted sulfonyl, substituted sulfonic acid, unsubstituted sulfonic acid, substituted phosphoryl, unsubstituted phosphoryl, substituted phosphonyl, unsubstituted phosphonyl, halogen, cyano, or hydroxyl;

A’ is a bond, absent, substituted aryl, unsubstituted aryl, substituted heteroaryl, unsubstituted heteroaryl, substituted C ₃-C ₂₀ cycloalkyl, unsubstituted C ₃-C ₂₀ cycloalkyl, substituted polyaryl, unsubstituted polyaryl, substituted polyheteroaryl, unsubstituted polyheteroaryl, substituted C ₃-C ₂₀ heterocyclyl, unsubstituted C ₃-C ₂₀ heterocyclyl, substituted C ₃-C ₂₀ cycloalkenyl, unsubstituted C ₃-C ₂₀ cycloalkenyl, substituted C ₃-C ₂₀ cycloalkynyl, unsubstituted C ₃-C ₂₀ cycloalkynyl, substituted alkyl, unsubstituted alkyl, substituted alkenyl, unsubstituted alkenyl, substituted alkynyl, unsubstituted alkynyl, substituted alkoxy, unsubstituted alkoxy, substituted aroxy, unsubstituted aroxy, substituted alkylthio, unsubstituted alkylthio, substituted arylthio, unsubstituted arylthio, substituted carbonyl, unsubstituted carbonyl, substituted carboxyl, unsubstituted carboxyl, substituted amino, unsubstituted amino, substituted amido, unsubstituted amido, substituted sulfonyl, unsubstituted sulfonyl, substituted sulfonic acid, unsubstituted sulfonic acid, substituted phosphoryl, unsubstituted phosphoryl, substituted phosphonyl, or unsubstituted phosphonyl; and

optionally, R ₃’ and R ₄’ together form R ₉’, wherein,

R ₉’ is unsubstituted alkylene, substituted alkylene, unsubstituted alkyl, substituted alkyl, substituted aryl, unsubstituted aryl, substituted heteroaryl, unsubstituted heteroaryl, substituted C ₃-C ₂₀ cycloalkyl, unsubstituted C ₃-C ₂₀ cycloalkyl, substituted polyaryl, unsubstituted polyaryl, substituted polyheteroaryl, unsubstituted polyheteroaryl, substituted C ₃-C ₂₀ heterocyclyl, unsubstituted C ₃-C ₂₀ heterocyclyl, substituted C ₃-C ₂₀ cycloalkenyl, unsubstituted C ₃-C ₂₀ cycloalkenyl, substituted C ₃-C ₂₀ cycloalkynyl, unsubstituted C ₃-C ₂₀ cycloalkynyl, substituted alkenyl, unsubstituted alkenyl, substituted alkynyl, unsubstituted alkynyl, substituted alkoxy, unsubstituted alkoxy, substituted aroxy, unsubstituted aroxy, substituted alkylthio, unsubstituted alkylthio, substituted arylthio, unsubstituted arylthio, substituted carbonyl, unsubstituted carbonyl, substituted carboxyl, unsubstituted carboxyl, substituted amino, unsubstituted amino, substituted amido, unsubstituted amido, substituted sulfonyl, unsubstituted sulfonyl, substituted sulfonic acid, unsubstituted sulfonic acid, substituted phosphoryl, unsubstituted phosphoryl, substituted phosphonyl, or unsubstituted phosphonyl.
A pharmaceutical composition comprising the compound of any one of claims 1-26 in an effective amount to alleviate or ameliorate one or more symptoms associated with a proliferative disorder, such as cancer.
The pharmaceutical composition of claim 27 or 28, further comprising one or more active or therapeutic agents.
A method for alleviation or amelioration of one or more symptoms associated with a proliferative disorder, such as cancer, comprising administering a compound of any one of claims 1-26 in an effective amount to a subject in need thereof.
A visualizing, tagging, or imaging method, comprising contacting a sample with a compound of any one of claims 1-26 in an effective amount, and viewing or detecting the sample when it is exposed to near a ultraviolet or visible radiation.
Use a compound of any one of claims 1-26 in the manufacture of a medication for alleviation or amelioration of one or more symptoms associated with a proliferative disorder, such as cancer.
Use a compound of any one of claims 1-26 in the manufacture of a visualization, tagging, or imaging agent.