CN110317294A - A kind of novel temperature sensitive fluorescent polymer of triphen amine and preparation method thereof - Google Patents

Abstract

A triphenylamine thermosensitive fluorescent polymer is synthesized by copolymerization of triphenylamine derivatives and N-isopropylacrylamide, which belongs to the field of polymer synthesis. The present invention adopts a reversible addition-fragmentation chain transfer polymerization method, uses methacryloyl chloride to introduce vinyl groups into triphenylamine derivatives to form polymerized monomers, and S-1-dodecyl-S'-(α,α"- Dimethyl‑α"‑acetic acid) trithiocarbonate is used as a chain transfer agent, and then it is copolymerized with N‑isopropylacrylamide using the reversible addition chain fragmentation transfer (RAFT) method to finally obtain triphenylamine thermosensitive Fluorescent polymer P (NIPAM‑co‑NDBM), which can be dissolved in water when the temperature is lower than the lowest critical solution temperature and has fluorescence, and has temperature-sensitive recovery and can be reused.

Description

A novel triphenylamine thermosensitive fluorescent polymer and its preparation method

technical field

The invention belongs to the field of organic functional macromolecules and macromolecular active polymerization, and specifically relates to a triphenylamine-based temperature-sensitive fluorescent polymer and a preparation method thereof. Firstly, 9,10-diphenyl-10-(4-aminobiphenyl)acridine is vinyl-functionalized to obtain a polymerizable monomer, which is copolymerized with NIPAM by reversible addition chain scission transfer polymerization, A fluorescent material with temperature-responsive properties is obtained, and this novel triphenylamine-based temperature-sensitive fluorescent copolymer has both fluorescence and temperature-sensitivity in characteristics. It will have broad application prospects in fluorescent thermometers, luminescent sensors, optical switching devices, etc.

technical background

Generally, triphenylamine and its derivatives have many advantages as fluorescent groups of organic probe molecules, such as strong ultraviolet absorption, adjustable fluorescence properties, emission wavelengths that can appear in the visible light region, and less damage to organisms. However, these triphenylamine-based small-molecule fluorescent probes usually exhibit poor water solubility and usually only function in the medium of pure organic solvents or aqueous solutions containing organic solvents. The lack of water solubility greatly limits its application in biological and environmental analysis. Therefore, the triphenylamine temperature-sensitive fluorescent probe material was constructed by incorporating small molecule probes into water-soluble polymers. Compared with small molecule probes, probes based on thermosensitive polymers have many advantages, such as good water solubility, fluorescence signal amplification, and probe recovery and reuse. After molecular design, different fluorescent units are formed, which can realize the enhancement of fluorescence intensity in aqueous solution.

Contents of the invention

The invention provides a triphenylamine thermosensitive fluorescent polymer material and a preparation method thereof. The triphenylamine-based fluorescent material is introduced into the double bond, and the triphenylamine-based fluorescent material is copolymerized with the temperature-sensitive material by reversible addition fragmentation transfer (RAFT) polymerization method, so as to obtain the triphenylamine-based fluorescent probe based on the temperature-sensitive polymer. Needle, the probe can be dissolved in aqueous solution below the lowest critical solution temperature, and has fluorescent properties.

Implementation method: use 9,10-diphenyl-10-(4-aminobiphenyl)acridine to react with methacryloyl chloride to obtain N-[9,10-diphenyl-10 -(4-aminobiphenyl) acridinyl] methacrylamide (formula I), its structure is:

In one embodiment, N-isopropylacrylamide and N-[9,10-diphenyl-10-(4-aminobiphenyl)acridinyl]methacrylic acid are combined by reversible addition chain scission transfer polymerization Under anhydrous and oxygen-free conditions, the amide is initiated by azobisisobutyronitrile and copolymerized to obtain a copolymer P(NIPAM-co-NDBM) (formula II), the molecular weight is controlled between 5000-10000, and its structure is :

Specific implementation method

Synthesis of N-[9,10-diphenyl-10-(4-aminobiphenyl)acridyl]methacrylamide

The synthetic route of N-[9,10-diphenyl-10-(4-aminobiphenyl)acridyl]methacrylamide is shown in Figure 1. Add 9,10-diphenyl-10-(4-aminobiphenyl)acridine (500mg, 1mmol), triethylamine (138.6μL, 1mmol), dichloromethane 20mL, 0 Stir at ℃ for 20 minutes, slowly add methacryloyl chloride (96.8 μL, 1 mmol) dropwise, react at 0°C for 10 minutes and then overnight at room temperature. After the reaction, add 100 mL of dichloromethane, wash with 0.1 mol/L HCl solution, 0.1 mol/L NaOH solution, and saturated sodium bicarbonate solution, and dry the organic layer with anhydrous sodium sulfate after washing, filter, and depressurize The solvent was distilled off, and the vacuum distillation residue was purified by silica gel column chromatography. The volume ratio of the eluent was 2:1 dichloromethane and normal hexane to obtain the compound shown in formula I as a white solid (499.8mg, 0.88 mmol), the yield was 88%.

The reaction formula is:

Synthesis of Triphenylamine Thermosensitive Fluorescent Polymers

The synthetic route of triphenylamine thermosensitive fluorescent polymer is shown in Figure 2. Add dodecyl trithiocarbonate (0.036g, 0.1mmol), azobisisobutyronitrile (0.002g, 0.01mmol), N-isopropylacrylamide (1.580g, 14mmol) respectively in a Schlenk bottle , N-(9,10-diphenyl-10-(4-aminobiphenyl)acridinyl)methacrylamide (0.114 g, 0.2 mmol), dioxane 4 mL, freeze-vacuum nitrogen-thaw , and this process is repeated three times. The reaction was carried out at 70°C for 18 hours. After the reaction was completed, it was settled with cold n-hexane and filtered to obtain 1.28 g of the product with a yield of 75%.

The reaction formula is:

Figure 1 is the infrared spectrum of N-[9,10-diphenyl-10-(4-aminobiphenyl)acridyl]methacrylamide

Figure 2 is N-[9,10-diphenyl-10-(4-aminobiphenyl)acridyl]methacrylamide H NMR spectrum

Fig. 3 is the infrared spectrogram of triphenylamine thermosensitive fluorescent polymer

Fig. 4 is the NMR spectrum of triphenylamine thermosensitive fluorescent polymer

Fig. 5 is the fluorescent emission spectrogram of triphenylamine thermosensitive fluorescent polymer dissolved in the mixed phosphate buffer solution (0.2g/L) of pH=6.86 at room temperature

Fig. 6 is a synthetic route diagram of a triphenylamine-based thermosensitive fluorescent polymer.

Claims (4)

1. A triphenylamine thermosensitive fluorescent polymer, characterized in that the polymer is N-[9,10-diphenyl-10-(4-aminobiphenyl)acridinyl]methacrylamide Copolymer with N-isopropylacrylamide, its chemical expression is: P(NIPAM-co-NDBM), number average molecular weight is 8000-16000, its structural formula is as follows: m and n are the degree of polymerization of the monomer, 60<m<100, 3<n<5. 2. the triphenylamine fluorescent substance monomer NDBM of a kind of triphenylamine temperature-sensitive fluorescent polymer according to claim 1, its synthetic method is as follows: 9,10-diphenyl-10-(4-amino-linked Phenyl)acridine reacts with methacryloyl chloride to obtain N-[9,10-diphenyl-10-(4-aminobiphenyl)acridyl]methacrylamide with vinyl, the reaction is as follows : 3. a kind of triphenylamine thermosensitive fluorescent polymer P (NIPAM-co-NDBM) according to claim 1, its synthetic method is as follows: monomer NDBM and N-isopropylpropylene according to claim 2 Amides are copolymerized by reversible addition fragmentation transfer (RAFT) polymerization method to obtain triphenylamine thermosensitive fluorescent polymer P (NIPAM-co-NDBM), the reaction is as follows: 4. a kind of triphenylamine thermosensitive fluorescent polymer P (NIPAM-co-NDBM) according to claim 1, when lower than its minimum critical solution temperature, possess good water solubility, and have fluorescence, high The recovery of P(NIPAM-co-NDBM) can be realized in LCST.