Donor-receptor type alternating polymer containing sulfone-based fused ring structure and having strong two-photon effect, preparation method and application
Technical Field
The invention belongs to the field of two-photon fluorescent polymers, and particularly relates to a donor-receptor type alternating polymer containing a sulfone-based fused ring structure and having a strong two-photon effect, and a preparation method and application thereof.
Background
Goppert-Mayer in 1931 first proposed the concept of two-photon absorption and theoretically calculated the transition probability of two-photon processes. The material passes through an intermediate virtual state (denoted by V in figure 1, V) under the action of intense light (such as laser light)1,V2May or may not be equal) and absorb the energy of two photons simultaneously (hv)1+hv2) Then, from the ground state S0Transition to excited state Sn(SnEnergy level of two photons) is called two-photon absorption (TPA). The first observation of this phenomenon by Kaiser in the experiments, which was limited by the experimental conditions, was not observed until the early 60 s laser, confirming the prediction of Goppert-Mayer. Two-photon absorption is a nonlinear optical phenomenon, and with the rapid progress of laser technology, researchers have made more and more intensive researches on two-photon absorption, except thatThe method is a spectrum result, and can be widely applied to the fields of three-dimensional information storage, two-photon up-conversion laser, two-photon absorption light amplitude limiting, two-photon fluorescence microscope, photodynamic therapy and the like.
The main characteristics of the material with strong two-photon absorption are that the molecular structure has a larger conjugated system and stronger electron-donating/electron-withdrawing ability. The sulfone group is a strong electron-deficient group, and is used for constructing a multi-element condensed ring structure, so that a new unit can retain the strong electron-withdrawing function of the sulfone group, and can show a strong intramolecular charge transfer effect when introduced into a molecular chain; and the new unit is endowed with better planarity and rigidity by the multi-element structure, so that the new unit has higher fluorescence quantum yield. The presence of sulfone groups favors the two-photon response of the polymeric material.
Disclosure of Invention
In order to overcome the defects and shortcomings in the prior art, the invention aims to provide a donor-acceptor type alternating polymer containing a sulfone-based fused ring structure and having a strong two-photon effect. The polymer is a D-A type polymer containing sulfonyl, and has the characteristics of good solubility, high fluorescence quantum yield and strong two-photon response.
The invention also aims to provide a preparation method of the donor-receptor type alternating polymer containing the sulfone fused ring structure and having the strong two-photon effect. The method takes a condensed ring structure containing the sulfone group as an electron-deficient unit, selects an electron-rich unit matched with the electron-deficient unit, and prepares the donor-acceptor type alternating polymer with the condensed ring structure containing the sulfone group and the strong two-photon effect through Suzuki polycondensation.
The invention further aims to provide the application of the sulfone-containing fused ring structure to the receptor-type alternating polymer with strong two-photon effect.
The purpose of the invention is realized by the following technical scheme:
a donor-acceptor type alternating polymer containing a sulfone-based fused ring structure and having a strong two-photon effect has a structural formula shown in formula (1):
wherein A is an electron-deficient unit and D is an electron-rich unit.
The structure of the electron-deficient unit A is any one of the following structures:
in the above preferred structural formula of the electron-deficient unit A, R is selected from H, C
1~C
30A linear or branched alkyl group of,
And
R
3selected from H, C
1~C
30And C is a straight or branched alkyl group
1~C
30Alkoxy group of (2).
The electron-rich unit D is any one of the following structural formulas:
in the preferable structural formula of the electron-rich unit D, R is selected from H, C
1~C
30A linear or branched alkyl group of,
And
R
3selected from H, C
1~C
30And C is a straight or branched alkyl group
1~C
30Alkoxy group of (a);
R
1、R
2、R
4~R
7can be the same or different and is independently selected from H, C
1~C
30Straight or branched alkyl of, C
1~C
30Alkoxy group of,
And
R
8selected from H, C
1~C
30And C is a straight or branched alkyl group
1~C
30Alkoxy group of (2).
The preparation of the donor-acceptor type alternating polymer containing the sulfone fused ring structure and having the strong two-photon effect mainly comprises the synthesis of an electron-deficient unit A and an electron-rich unit D.
The preparation of the donor-acceptor type alternating polymer containing the sulfone fused ring structure and having the strong two-photon effect is obtained by Suzuki polymerization of the sulfone fused ring structure A and an electron-rich unit D.
Further, the preparation method of the donor-receptor type alternating polymer containing the sulfone fused ring structure and having the strong two-photon effect comprises the following steps:
(1) under the atmosphere of inert gas, dissolving the sulfonyl condensed ring structure monomer A and the electron-rich unit D by using toluene, adding palladium acetate, tricyclohexyl phosphorus and tetraethylammonium hydroxide aqueous solution, heating and stirring, and reacting for 24-36 hours at the temperature of 60-110 ℃;
(2) adding phenylboronic acid for end capping, and continuing to react for 6-12 hours; adding bromobenzene for end sealing, and continuing to react for 6-12 hours;
(3) after the polymerization is finished, precipitating the reaction solution in methanol, filtering, sequentially extracting with methanol, acetone and n-hexane, then using toluene as eluent, carrying out column chromatography on a silica gel column, concentrating, precipitating again in a methanol solution, filtering, and drying to obtain the donor-receptor type alternating polymer containing the sulfone-based fused ring structure and having the strong two-photon effect.
Further, the inert gas in step (1) comprises argon;
further, the molar ratio of the electron-deficient unit A to the electron-donating unit D in the step (1) is 1: 1;
further, the molar ratio of the palladium acetate, the tricyclohexylphosphorus and the electron-deficient unit A in the step (1) is 1: 2: 100 to 150 parts;
furthermore, the volume ratio of the tetraethylammonium hydroxide aqueous solution to the toluene in the step (1) is 1: 6-10.
Further, the phenylboronic acid described in step (2): bromobenzene: the molar ratio of the electron-deficient units is 0.2-0.5: 2-5: 1.
the application of the donor-receptor type alternating polymer containing the sulfone fused ring structure and having the strong two-photon effect in the field of nonlinear optics comprises the application in the aspects of two-photon fluorescence microscopy, two-photon up-conversion laser, light amplitude limiting, two-photon three-dimensional processing, two-photon three-dimensional optical storage, two-photon photodynamic therapy and the like.
Further, in the application process, the strength of the two-photon absorption performance of the sulfone-containing fused ring structure with strong two-photon effect on the receptor-type alternating polymer is measured by a two-photon absorption cross section, and the larger the two-photon absorption cross section value is, the stronger the two-photon absorption capacity of the compound containing the S, S-dioxo-dibenzothiophene unit is, and the faster the response is.
Furthermore, the two-photon absorption cross section is tested in the following manner: dissolving the donor-acceptor type alternating polymer with the strong two-photon effect and containing the sulfone-based fused ring structure by using an organic solvent, and testing by using a two-photon induced fluorescence method, a Z-scanning technology, a nonlinear transmittance method or a two-photon transient absorption spectrometry.
Still further, the organic solvent includes toluene, xylene, N-hexane, diethyl ether, dioxane, dichloromethane, chloroform, ethyl acetate, tetrahydrofuran, 1, 2-dichloroethane, N-dimethylformamide, N-dimethylacetamide, acetone, dimethylsulfoxide, or chlorobenzene.
Compared with the prior art, the invention has the following advantages and beneficial effects:
(1) in the donor-receptor type alternating polymer with the sulfone-containing condensed ring structure and the strong two-photon effect, the sulfone group is a strong electron-deficient group, and the electronegativity is stronger than that of fluorine, ester group, carbonyl and the like, so that the unit of the condensed ring structure containing the sulfone group has strong electron-withdrawing capability, the intramolecular charge transfer effect among the electron-rich units connected with the unit is strong, and the two-photon absorption response of the polymer can be greatly improved.
(2) The donor-receptor type alternating polymer containing the sulfone fused ring structure and having the strong two-photon effect has higher fluorescence quantum yield due to the larger conjugation length, and is beneficial to enhancing the two-photon absorption capability of the compound.
(3) The sulfone-containing fused ring structure with strong two-photon effect has strong single-photon fluorescence and two-photon fluorescence intensity for receptor type alternating polymers, has good solubility, can be dissolved in common organic solvents, is convenient for testing and applying two-photon absorption performance, and has practical application value in the field of nonlinear optics.
Drawings
FIG. 1 is a two-photon absorption (TPA) energy diagram;
FIG. 2 is a single photon fluorescence spectrum of polymer P1 in different polar solvents;
FIG. 3 is a two-photon fluorescence spectrum of polymer P2 in toluene solution at different laser wavelengths;
FIG. 4 is a graph of two-photon absorption cross-section of polymer P1 in different polar solvents versus laser wavelength;
FIG. 5 is a graph showing the relationship between the two-photon absorption cross section and the laser wavelength of polymers P2-P4 in a toluene solution.
Detailed Description
The present invention will be described in further detail with reference to examples and drawings, but the embodiments of the present invention are not limited thereto. It is intended that the appended claims cover all such modifications as fall within the true spirit and scope of the invention, as defined by the following claims, and all changes to the embodiments of the invention which fall within the true spirit and scope of the invention.
Example 1: synthesis of 1, 4-dihexyloxybenzene
To a 500ml two-necked flask, under an argon atmosphere, p-diphenol (11g, 0.10mol), tetrabutylammonium bromide (0.32g, 1.00mmol), a 50 wt% aqueous sodium hydroxide solution (20g/20ml deionized water, 0.5mmol), and toluene solvent (200ml) were added. Heated with stirring and, when the temperature stabilized to 80 ℃, n-hexyl bromide (36.31g, 0.22mmol) was added. After 6 hours of reaction, the reaction was terminated, the organic layer was separated, concentrated and the crude product was purified by column chromatography using petroleum ether as eluent to give 25.1g of a white solid in 91% yield.1H NMR、13The results of C NMR, MS and elemental analysis show that the obtained compound is the target product, and the chemical reaction equation is as follows:
example 2: synthesis of 1, 4-dibromo-2, 5-dihexyloxybenzene
1, 4-dihexyloxybenzene (10g, 35.9mmol) and carbon tetrachloride (150ml) were added to a 250ml single-neck reaction flask under exclusion of light, and liquid bromine (12.6g, 79.0mmol) was added three times. After 8 hours of reaction, saturated sodium bisulfite solution was added, extracted with dichloromethane, the organic phase collected, concentrated and the crude product recrystallized from ethanol to yield 13.47g of white needle crystals, yield: 86 percent.1H NMR、13The results of C NMR, MS and elemental analysis show that the obtained compound is the target product, and the chemical reaction equation is as follows:
example 3: synthesis of 2, 2' - (2, 5-dihexyloxy) -1, 4-phenyl-bis 4,4,5, 5-tetramethyl-1, 3, 2-dioxaborane
A250 mL three-necked flask was charged with 1, 4-dibromo-2, 5-dihexyloxybenzene (15g,34.4mmol) and 100mL of anhydrous tetrahydrofuran. A2.4M n-butyllithium/n-hexane solution (35.8mL,86mmol) was added dropwise at-78 ℃ under an argon atmosphere and stirred at-78 ℃ for 2 h. 2-Isopropoxy-4, 4,5, 5-tetramethyl-1, 3, 2-ethylenedioxyboronate (19.3mL,96.3mmol) was then added rapidly and stirring continued at-78 deg.C for 1.5 h. The reaction mixture was gradually warmed to room temperature and stirred for 10 h. The reaction solution was spin dried, extracted with ethyl acetate, washed with aqueous NaCl, dried over anhydrous magnesium sulfate, and concentrated, and the crude product was purified by silica gel column chromatography, eluent petroleum ether/dichloromethane (3:1) to give 10.2g of a white solid, yield: 56 percent.1H NMR、13The results of C NMR, MS and elemental analysis show that the obtained compound is the target product, and the chemical reaction equation is as follows:
example 4: 2 ', 5' -dihexyloxy-2 '2 "-dimesylate-1, 1'; synthesis of 4 '1' -terphenyl
Under the protection of argon, 2' - (2, 5-dihexyloxy) -1, 4-phenyl-bis 4,4,5, 5-tetramethyl-1, 3, 2-dioxaborane (9.21g, 50mmol), 1-bromo-2-methanesulfonamide (), tetrabutylammonium bromide (), tetratriphenylphosphine palladium (), and 100ml of a toluene solvent were sequentially added to a 250ml three-necked flask, stirred and heated to 110 ℃, and a 50 wt% potassium carbonate aqueous solution (24.6ml, 125mmol) was added to react for 24 hours; the solvent was dried by spinning and the crude product was purified by column chromatography on silica gel eluting with petroleum ether/dichloromethane (4:1) to give 10.2g of a pale yellow viscous liquid, yield: 74 percent.1H NMR、13The results of C NMR, MS and elemental analysis show that the obtained compound is the target product, and the chemical reaction equation is as follows:
example 5: synthesis of Compound M1
2 ', 5 ' -dihexyloxy-2 ', 2 ' -dimethylsulfinyl-1, 1 '; 4' 1 "-terphenyl (8.6g,15.5mmol) was added to 10mL of trifluoromethanesulfonic acid, stirred at room temperature for 20h, after which the reaction was added dropwise to ice water. Then, the reaction solution was filtered with suction to obtain a pale yellow solid powder, which was then dried. The pale yellow solid powder was added to 100mL of pyridine and heated under reflux for 6h under nitrogen. The reaction was stopped and cooled to room temperature, extracted and excess pyridine was neutralized with hydrochloric acid. Column chromatography on pure petroleum ether and recrystallization from ethanol gave a yellow powdery solid (2.43g, 32%).1H NMR、13The results of C NMR, MS and elemental analysis show that the obtained compound is the target product, and the chemical reaction equation is as follows:
example 5: synthesis of Compound M2
Compound M1(1.80g, 3.67mmol) and iodine (46mg, 0.18mmol) were added to 40ml dichloromethane, and liquid bromine (1.29g, 8.07mmol) was added dropwise under exclusion of light for reaction for 10 hours; adding saturated sodium bisulfite water solution into the reaction system, separating the organic phase when the system is colorless, concentrating, purifying the crude product by column chromatography with petroleum ether as eluent to obtain 1.55g yellow solid with yield of 65%.1H NMR、13The results of C NMR, MS and elemental analysis show that the obtained compound is the target product, and the chemical reaction equation is as follows:
example 6: synthesis of Compound M3
Compound M2(1.2g, 1.85mmol) and 3-chloroperoxybenzoic acid (3.4g,20mmol) were dissolved in 120mL of dichloromethane, and after stirring for 5 hours, the reaction solution was poured into a cold aqueous solution of 10% by mass of sodium hydroxide and stirred for 30 minutes. Washing the organic layer with water three times, collecting the organic phase, concentrating and purifying by chromatography column, wherein the eluent isDichloromethane/ethyl acetate (volume ratio: 1:2) and then recrystallization from ethanol gave a yellow solid (1.12g, 85%).1H NMR、13The results of C NMR, MS and elemental analysis show that the obtained compound is the target product, and the chemical reaction equation is as follows:
example 7: synthesis of 4-n-octyl triphenylamine
Dissolving 4-octylbromobenzene (2.69g, 10mmol) and aniline (0.93g, 23mmol) in 150mL of toluene complete solution, adding sodium tert-butyl alkoxide (3.94g, 41mmol) and palladium acetate (96mg, 0.5mmol), heating the oil bath to 85 ℃ under the protection of argon, and continuing to add a toluene solution of tri-tert-butylphosphine (1.0mol/L, 0.5 mL); after reacting for 12 hours, adding water into the reaction solution to quench the reaction, extracting with dichloromethane for three times, washing an organic phase with deionized water for three times, drying, concentrating, separating and purifying a crude product by using a silica gel column chromatography, and using pure petroleum ether as an eluent to obtain a white solid. The yield was 82%.1H NMR、13The results of C NMR, MS and elemental analysis show that the obtained compound is the target product, and the chemical reaction equation is as follows:
example 8: synthesis of 4,4 '-dibromo-4' -octyl triphenylamine
Completely dissolving 4-N-octyl triphenylamine (2.50g, 7mmol) in 20ml of N, N-dimethylformamide, dropwise adding a solution of N-bromosuccinimide (NBS, 2.74g, 15.4mmol) in N, N-dimethylformamide at the temperature of 0 ℃, and reacting for 4 hours in the dark; pouring the reaction liquid into water, stirring, filtering, separating and purifying the filter cake by silica gel column chromatography, and taking pure petroleum ether as eluent to obtain white solid. The yield was 78%.1H NMR、13The results of C NMR, MS and elemental analysis show that the obtained compound is the target product, and the chemical reaction equation is as follows:
example 9: synthesis of 4,4 ' -bis (4,4 ', 5,5 ' -tetramethyl-1, 3, 2-dioxaborane-diyl) -phenyl) -4 "-octyltriphenylamine
4,4 '-dibromo-4' -octyltriphenylamine (2.58g, 5mmol) was completely dissolved in 100ml of anhydrous Tetrahydrofuran (THF) solution, and then the temperature was lowered to-78 ℃ under the protection of argon, and 5.3ml of an n-hexane solution of n-butyllithium (2.4 mol L concentration) was added dropwise-1) After reacting for 1 hour, adding 2-isopropoxy-4, 4,5, 5-tetramethyl-1, 3, 2-ethylenedioxy boric acid ester (2.6g, 14mmol) at one time, and continuing stirring for 2 hours; gradually raising the reaction system to normal temperature for reaction for 24 hours; concentrating the reaction solution, sequentially extracting with ethyl acetate for three times, washing the organic phase with deionized water for three times, drying, concentrating, separating and purifying the crude product by silica gel column chromatography, and using a petroleum ether/ethyl acetate (5/1, v/v) mixed solvent as an eluent to obtain a white solid. The yield was 69%.1HNMR、13The results of C NMR, MS and elemental analysis show that the obtained compound is the target product, and the chemical reaction equation is as follows:
example 10: synthesis of 3, 6-dibromocarbazole
Completely dissolving carbazole (1.67g, 10mmol) by 300ml of dichloromethane solution, adding 30g of 100-mesh 200-mesh silica gel, adding N-bromosuccinimide (NBS, 3.92g, 22mmol) in three batches under the ice bath condition (0 ℃), and reacting for 12 hours under the dark condition; the reaction solution is filtered by suction, a filter cake is washed by dichloromethane for 5 times, an organic phase is collected, dried and concentrated, and a crude product is recrystallized by dichloromethane/petroleum ether (5/100, v/v) for three times to obtain a white solid. The yield was 83%.1H NMR、13The results of C NMR, MS and elemental analysis show that the obtained compound is the target product, and the chemical reaction equation is as follows:
example 11: synthesis of 3, 6-dibromo-N-isooctylcarbazole
Completely dissolving 3, 6-dibromocarbazole (2.28g, 7mmol) by using 80ml of toluene solution, adding tetrabutylammonium bromide (0.11g, 0.35mmol), heating the oil bath to 85 ℃ under the protection of argon, continuously adding 50 wt% of sodium hydroxide (2.8g/2.8ml of deionized water, 70mmol) aqueous solution, stirring for 1 hour, and quickly adding isooctyl bromide (2.03g, 10.5 mmol); after 8 hours of reaction, adding water into the reaction solution to quench the reaction, extracting with dichloromethane for three times, washing the organic phase with deionized water for three times, drying, concentrating, separating and purifying the crude product by silica gel column chromatography, and using pure petroleum ether as eluent to obtain white solid. The yield was 94%.1H NMR、13The results of C NMR, MS and elemental analysis show that the obtained compound is the target product, and the chemical reaction equation is as follows:
example 12: synthesis of 3, 6-bis (4,4 ', 5, 5' -tetramethyl-1, 3, 2-dioxaborane-diyl) -N-isooctylcarbazole
Completely dissolving 3, 6-dibromo-N-isooctylcarbazole (2.19g, 5mmol) in 100ml of anhydrous THF, cooling to-78 ℃ under the protection of argon, and dropwise adding 2.4mol L of the solution-1After reacting for 1 hour with a solution of n-butyllithium in n-hexane (5.3ml, 12.5mmol), 2-isopropoxy-4, 4,5, 5-tetramethyl-1, 3, 2-ethylenedioxy borate (2.79g, 15mmol) was added at a time, and stirring was continued for 2 hours. Gradually raising the reaction system to normal temperature for reaction for 24 hours; concentrating the reaction solution, sequentially extracting with ethyl acetate for three times, washing the organic phase with deionized water for three times, drying, concentrating, separating and purifying the crude product by silica gel column chromatography, and using a petroleum ether/ethyl acetate (6/1, v/v) mixed solvent as an eluent to obtain a white solid. The yield was 67%.1H NMR、13The results of C NMR, MS and elemental analysis show that the obtained compound is the target product, and the chemical reaction equation is as follows:
example 13: synthesis of 2, 7-dibromo-N-isooctylcarbazole
Completely dissolving 2, 7-dibromocarbazole (3.25g, 10mmol) by using 80ml of toluene, adding tetrabutylammonium bromide (0.16g, 0.5mmol), heating the solution to 85 ℃ in an oil bath under the protection of argon, continuously adding 50 wt% of sodium hydroxide (4.0g/4.0ml of deionized water and 0.1mol) aqueous solution, stirring for 1 hour, and quickly adding isooctyl bromide (2.32g, 12 mmol); after 8 hours of reaction, adding water into the reaction solution to quench the reaction, extracting with dichloromethane for three times, washing the organic phase with deionized water for three times, drying, concentrating, separating and purifying the crude product by silica gel column chromatography, and using pure petroleum ether as eluent to obtain white solid. The yield was 94%.1H NMR、13The results of C NMR, MS and elemental analysis show that the obtained compound is the target product, and the chemical reaction equation is as follows:
example 14: synthesis of 2, 7-bis (4,4 ', 5, 5' -tetramethyl-1, 3, 2-dioxaborane-diyl) -N-isooctylcarbazole
Dissolving 2, 7-dibromo-N-isooctylcarbazole (3.5g, 8mmol) completely in 100ml of anhydrous Tetrahydrofuran (THF) solution, cooling to-78 ℃ under the protection of argon, and dropwise adding 2.4mol L of-1After reacting for 1 hour with a solution of n-butyllithium in n-hexane (8.4ml, 20mmol), 2-isopropoxy-4, 4,5, 5-tetramethyl-1, 3, 2-ethylenedioxy borate (4.17g, 22.4mmol) was added at a time, and stirring was continued for 2 hours; gradually raising the reaction system to normal temperature for reaction for 24 hours; concentrating the reaction solution, sequentially extracting with ethyl acetate for three times, washing the organic phase with deionized water for three times, drying, concentrating, separating and purifying the crude product by silica gel column chromatography, and using a petroleum ether/ethyl acetate (6/1, v/v) mixed solvent as an eluent to obtain a white solid. The yield was 67%.1H NMR、13C NMR, MS and element analysis results show that the obtained compound is a target product and is subjected to chemical reactionThe equation should be as follows:
example 15: synthesis of cyclohexane-1, 4-dicarbonyl-bis (3-bromophenyl) hydrazone
Dissolving 3-bromophenylhydrazine hydrochloride (11.2g, 50mmol) and sodium acetate (4.1g, 50mmol) in 200ml ethanol, and stirring and mixing uniformly; under the protection of argon, an ethanol solution (100ml) of 1, 4-cyclohexanedione (2.81g, 25mmol) is slowly added, and then the mixture is heated to 60 ℃ in an oil bath to react for 5 hours; and after the reaction is stopped, pouring the reaction liquid into ice water, stirring, performing suction filtration to separate a filter cake, washing with glacial ethanol to obtain a brown solid, wherein the yield is 75%, drying the solid, performing low-temperature light-shielding treatment, and directly using the solid in the next reaction without treatment.1H NMR、13The results of C NMR, MS and elemental analysis show that the obtained compound is the target product, and the chemical reaction equation is as follows:
example 16: synthesis of 3, 9-dibromoindole [3,2-b ] carbazole
Dissolving cyclohexane-1, 4-dicarbonyl-bis (3-bromophenyl) hydrazone (5.0g, 11mmol) in 100ml of glacial acetic acid/concentrated sulfuric acid mixed solution (volume ratio of 4/1), and stirring and mixing uniformly under the ice bath condition; then, heating the mixture to 50 ℃ in an oil bath, and reacting for 5 hours; then heating to 90 ℃ and reacting for 12 hours; after the reaction is stopped, the reaction solution is poured into ice water, stirred, filtered to separate a filter cake, washed by using glacial ethanol to obtain a tawny crude product, and recrystallized by using DMF to obtain a yellowish green needle-shaped solid with the yield of 25%.1H NMR、13The results of CNMR, MS and element analysis show that the obtained compound is a target product, and the chemical reaction equation is as follows:
example 17: synthesis of 3, 9-dibromo-5, 11-di (9-hexadecyl) indole [3,2-b ] carbazole
Dissolving 3, 9-dibromoindole [3,2-b ] in 40ml dimethyl sulfoxide solution]Carbazole (2.0g, 4.8mmol), tetrabutylammonium bromide (154mg, 0.48 mmol); under the protection of argon, raising the temperature of the oil bath to 60 ℃, continuously adding 50 wt% of sodium hydroxide (2.7g/2.7ml of deionized water, 48mmol) aqueous solution, stirring for 1 hour, and quickly adding bromohexadecane (4.4g, 14.2 mmol); after 12 hours of reaction, the reaction solution was poured into ice water, stirred, filtered to separate the filter cake, and washed with ethanol to give a yellow solid with a yield of 91%.1H NMR、13The results of C NMR, MS and elemental analysis show that the obtained compound is the target product, and the chemical reaction equation is as follows:
example 18: synthesis of 3, 9-bis (4,4 ', 5, 5' -tetramethyl-1, 3, 2-dioxaborane-diyl) -5, 11-bis (9-hexadecyl) indole [3,2-b ] carbazole
Dissolving 3, 9-dibromo-5, 11-di (9-heptadecyl) indole [3,2-b ] in 50ml of dioxane solution]Carbazole (1.0g, 1.1mmol) and bis (pinacolato) borate (0.9g, 3.5mmol) are subjected to oil bath heating to 80 ℃ under the protection of argon, 1' -bis (diphenylphosphino) ferrocene palladium dichloride (40mg, 55 mu mol) is rapidly added for reaction for 12 hours; after the reaction is stopped, the reaction solution is concentrated, ethyl acetate is used for extracting for three times in sequence, the organic phase is washed for three times by deionized water, then drying and concentrating are carried out, the crude product is separated and purified by silica gel column chromatography, and a petroleum ether/ethyl acetate (5/1, v/v) mixed solvent is used as an eluent, so that light yellow solid is obtained. The yield was 56%.1H NMR、13The results of C NMR, MS and elemental analysis show that the obtained compound is the target product, and the chemical reaction equation is as follows:
the following are examples of polymerization reactions, applicable to any of the same types of polymerization reactions.
Example 19: polymer P1 Synthesis
4,4 ' -bis (4,4 ', 5,5 ' -tetramethyl-1, 3, 2-dioxaborane-diyl) -phenyl) -4 "-octyltriphenylamine (304.7mg,0.50mmol) and compound M3(356.2mg,0.50mmol) were dissolved in 12ml of toluene under an argon atmosphere, and an aqueous tetraethylhydroxylamine solution (1.5ml, wt% ═ 20%), palladium acetate (1.12mg, 5 μmol) and tricyclohexylphosphine (2.8mg, 10 μmol) were added; after heating to 80 ℃ for reaction for 24 hours, adding phenylboronic acid (15mg, 0.13mmol) for end capping for 6 hours, and then adding bromobenzene (0.25ml, 2.0mmol) for end capping for 6 hours; stopping reaction, cooling, precipitating the organic phase in methanol (200ml), filtering, drying, extracting the crude product with methanol, acetone and n-hexane successively, dissolving the polymer with toluene, eluting with toluene, and purifying with neutral alumina column chromatography; the toluene solution of the polymer was concentrated, and precipitated again in a methanol solution, filtered, and dried to obtain a fibrous polymer.
FIG. 2 is a single photon fluorescence spectrum of polymer P1 in different polar solvents, i.e., toluene with low polarity, tetrahydrofuran with medium polarity, dichloromethane, and N, N-dimethylformamide with high polarity. The maximum single-photon fluorescence intensity of the polymer in different solvents is weakened along with the increase of the polarity of the solvent, and the maximum fluorescence intensity in a toluene solvent is 1.58 multiplied by 107(ii) a The maximum emission peak is red-shifted from 525nm (toluene solvent) to 572nm (N, N-dimethylformamide solvent), and intramolecular charge transfer is obvious. This contributes to enhancement of the two-photon absorption ability.
Example 20: polymer P2 Synthesis
3, 6-bis (4,4 ', 5, 5' -tetramethyl-1, 3, 2-dioxaborane-diyl) -N-isooctylcarbazole (265.7mg,0.50mmol) and compound M3(356.2mg,0.50mmol) were dissolved in 12ml of toluene under argon protection, and an aqueous tetraethylhydroxylamine solution (1.5ml, wt% ═ 20%), palladium acetate (1.12mg, 5 μmol) and tricyclohexylphosphine (2.8mg, 10 μmol) were added; after heating to 80 ℃ for reaction for 24 hours, adding phenylboronic acid (15mg, 0.13mmol) for end capping for 6 hours, and then adding bromobenzene (0.25ml, 2.0mmol) for end capping for 6 hours; stopping reaction, cooling, precipitating the organic phase in methanol (200ml), filtering, drying, extracting the crude product with methanol, acetone and n-hexane successively, dissolving the polymer with toluene, eluting with toluene, and purifying with neutral alumina column chromatography; the toluene solution of the polymer was concentrated, and precipitated again in a methanol solution, filtered, and dried to obtain a fibrous polymer.
FIG. 3 is a two-photon fluorescence spectrum of polymer P2 in toluene solution at different laser wavelengths; as can be seen from the graph, when the laser wavelength was gradually increased from 720nm to 940nm, the two-photon fluorescence intensity of the polymer P2 was 103Above, when the laser wavelength is 760nm, the two-photon fluorescence intensity of the polymer is 1.97X 10 at the maximum5And higher fluorescence intensity indicates that the polymer has stronger two-photon response.
Example 21: polymer P3 Synthesis
2, 7-bis (4,4 ', 5, 5' -tetramethyl-1, 3, 2-dioxaborane-diyl) -N-isooctylcarbazole (265.7mg,0.50mmol) and compound M3(356.2mg,0.50mmol) were dissolved in 12ml of toluene under argon protection, and an aqueous tetraethylhydroxylamine solution (1.5ml, wt% ═ 20%), palladium acetate (1.12mg, 5 μmol) and tricyclohexylphosphine (2.8mg, 10 μmol) were added; after heating to 80 ℃ for reaction for 24 hours, adding phenylboronic acid (15mg, 0.13mmol) for end capping for 6 hours, and then adding bromobenzene (0.25ml, 2.0mmol) for end capping for 6 hours; stopping reaction, cooling, precipitating the organic phase in methanol (200ml), filtering, drying, extracting the crude product with methanol, acetone and n-hexane successively, dissolving the polymer with toluene, eluting with toluene, and purifying with neutral alumina column chromatography; the toluene solution of the polymer was concentrated, and precipitated again in a methanol solution, filtered, and dried to obtain a fibrous polymer.
Example 22: polymer P4 Synthesis
3, 9-bis (4,4 ', 5, 5' -tetramethyl-1, 3, 2-dioxaborane-diyl) -5, 11-bis (9-hexadecyl) indole [3,2-b ] carbazole (478.6mg,0.50mmol) and the compound M3(356.2mg,0.50mmol) were dissolved in 12ml of toluene under argon protection, and an aqueous tetraethylhydroxylamine solution (1.5ml, 20% by weight), palladium acetate (1.12mg, 5 μmol) and tricyclohexylphosphine (2.8mg, 10 μmol) were added; after heating to 80 ℃ for reaction for 24 hours, adding phenylboronic acid (15mg, 0.13mmol) for end capping for 6 hours, and then adding bromobenzene (0.25ml, 2.0mmol) for end capping for 6 hours; stopping reaction, cooling, precipitating the organic phase in methanol (200ml), filtering, drying, extracting the crude product with methanol, acetone and n-hexane successively, dissolving the polymer with toluene, eluting with toluene, and purifying with neutral alumina column chromatography; concentrating the toluene solution of the polymer, precipitating again in methanol solution, filtering, and drying to obtain fibrous polymer
Example 23: two-photon absorption Performance test of Donor-acceptor type alternating Polymer containing sulfone-based fused Ring Structure
Testing the two-photon absorption performance of the donor-receptor type alternating polymer containing the sulfone fused ring structure by a two-photon fluorescence induction method; during experimental tests, a titanium-sapphire femtosecond laser (Avesta TiF-100M) is used as a pumping light source, the pulse width of the laser is 80fs, the frequency is 84.5Hz, the laser excitation energy is 100mw, and the light transmission length of the pulse is 10 mm. Dissolving a polymer P1 in four solvents with different polarities, namely toluene, tetrahydrofuran, dichloromethane and N, N-dimethylformamide; polymers P2-P4 were dissolved in toluene solution, all at a concentration of 1X 10- 6mol L-1. The standard sample is 0.1mol L of fluorescein-1Concentrated in aqueous sodium hydroxide solutionDegree of 1X 10-6mol L-1The fluorescence quantum yield was 88%. The results of the fluorescence quantum yield test of the polymers P1-P4 in the solution state are shown in Table 1.
TABLE 1 fluorescence quantum yields of polymers P1-P4
As can be seen from table 1, the fluorescence quantum yield of polymer P1 was 73% in the toluene solution state, and decreased to 5% as the solvent polarity increased to N, N-dimethylformamide. This indicates that the polymer P1 has strong two-photon response potential in weak polar toluene solution. It has also been shown that the polarity of the solvent is an important factor in the two-photon response of the polymer. The fluorescence quantum yields of the polymers P1-P4 in the toluene solution are 73%, 51%, 65% and 67%, respectively, and the higher fluorescence quantum yield shows that the polymers have great application prospects in the application field of two-photon absorption.
The two-photon absorption cross section delta of the compound can be calculated according to the fluorescence quantum yield and the two-photon fluorescence spectrum of the polymer, and the calculation formula is as follows:
in the above formula, 1 represents 0.1mol L of the standard, fluorescein-1An aqueous sodium hydroxide solution of (a); and 2 represents a sample to be tested. I is1、I2And the integral areas of the two-photon fluorescence spectra of the standard sample and the sample to be detected are shown, and the two-photon fluorescence spectra are shown in 2 and 3. Phi is a1、φ2And (4) expressing the fluorescence quantum efficiency of the standard sample and the sample to be detected. C1、C2And (4) representing the solution concentration of the standard sample and the sample to be detected.
The relationship between the two-photon absorption cross section of the polymer P1 in different solvents and the laser wavelength is shown in FIG. 4, and it can be seen from the graph that the two-photon absorption cross section of the polymer P1 has the same trend with the change of the laser wavelength in the state of different polar solvents. Two-photon of the polymer P1 at laser wavelengths of 760nm and 800nmThe absorption cross-section value is large. The largest among them was 3657GM (1GM ═ 10) in toluene solvent-50cm-4sphoton-1) The laser wavelength is 760 nm;
when the laser wavelength is 800nm, the maximum two-photon absorption cross section value of the polymer P1 in a tetrahydrofuran solvent is 348 GM;
when the laser wavelength is 780nm, the maximum two-photon absorption cross section value of the polymer P1 in an N, N-dimethylformamide solvent is 108 GM;
from the two-photon absorption cross section data of the polymer P1 in solvents with different polarities, it can be known that the polarity of the solvent has an important influence on the two-photon absorption performance of the material. And the proper solvent is selected to be beneficial to the exhibition of the two-photon absorption performance of the material.
The relationship between the two-photon absorption cross section of the polymers P2-P4 in toluene solvent and the laser wavelength is shown in FIG. 5, and it can be seen from the graph that the maximum two-photon absorption cross section value of the polymer P2 is 1308GM when the laser wavelength is 780 nm;
when the laser wavelength is 720nm, the two-photon absorption cross section value of the polymer P3 is 1005GM at most;
when the laser wavelength is 780nm, the maximum two-photon absorption cross section value of the polymer P4 is 784 GM;
the polymers P1-P4 have larger two-photon absorption cross section values in the whole test range, which shows that the sulfone group-containing fused ring structure has good two-photon response for receptor type alternating polymers and has practical application value.
The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.