CN101845040B - Organic second-order nonlinear optical chromophore with D-pi-A structure modified by dendritic group, and synthetic method and application thereof - Google Patents

Abstract

The invention relates to a dendritic group modified organic second-order nonlinear optical chromophore with a D-pi-A structure, a synthetic method and application thereof. The chromophore of the invention introduces a thiophene ring conjugated pi electron bridge with a branched chain with strong electron transmission capability and a tricyano pyrroline receptor with strong electron-withdrawing capability, and the receptor end introduces a dendritic modification group, so that the hyperpolarizability of the first-order molecule of the chromophore molecule is greatly improved, the solubility and the film-forming property of the chromophore in a polymer are improved, and the interaction force among molecules is reduced. The organic second-order nonlinear optical chromophore of the invention with the following structure is doped with polymers such as amorphous polycarbonate or polymethyl methacrylate and the like according to the mass ratio of 1: 10, and the electro-optic coefficient of the obtained polarized polymer material can reach 217 pm/V. In addition, the chromophore donor and the acceptor end of the invention can be introduced with crosslinkable groups, thereby improving the orientation stability of the chromophore in the polymer and meeting the requirements of device formation.

Description

Dendritic group-modified organic second-order nonlinear optical chromophore with D-π-A structure and its synthesis method and application

technical field

The invention relates to the field of organic second-order nonlinear optical materials, in particular to an organic second-order nonlinear optical chromophore with a D-π-A structure modified by a dendritic group with high electro-optic activity and its synthesis method and application .

Background technique

In the current society, laser and optical fiber communication are replacing microelectronics and integrated circuit technology and becoming emerging communication technologies. As two cutting-edge disciplines of laser communication and optical fiber communication: integrated optics and optoelectronics have achieved rapid development. The integrated optical system includes important devices such as waveguides, optical switches, and optical converters, and nonlinear optical materials must be used in these devices. At present, the nonlinear optical materials that are widely used in practice are mainly inorganic crystal materials. Compared with inorganic crystal materials, organic second-order nonlinear optical materials have high nonlinear optical coefficient, fast response speed (sub-picosecond or even picosecond), and relatively large nonlinear optical response (usually 1-2 times higher than inorganic crystal materials). order of magnitude), high optical damage threshold (GW/cm2 level), low absorption coefficient, low dielectric constant, high bandwidth, molecular design according to requirements, easy processing and low cost, etc., so it has broad application prospects.

Since the response of organic nonlinear optical materials is closely related to the nonlinear optical properties of chromophore molecules, in order to meet the requirements of practical applications, it is necessary to design chromophore molecules and effectively convert the second-order nonlinear properties of chromophores into The electro-optical performance of materials is to be carried out in two aspects: one is to seek chromophore molecules with large first-order molecular hyperpolarizability (β value) and excellent comprehensive performance; The chromophore density per unit volume of the material is relatively large, and the chromophore can obtain better orientation consistency and good stability through electric polarization, so that the first-order molecular hyperpolarizability (β value) of the chromophore is effective. Converted to the electro-optic coefficient (r ₃₃ ) of the macroscopic material.

In the existing reports on organic second-order nonlinear optical materials, most of the macroscopic electro-optic coefficients are not high. A series of chromophores containing pyrroline electron acceptors reported in Chem.Mater., Vol.18, No.13, 2006 and US Patent No. 7307173B1 have higher first-order molecular hyperpolarizability, but these chromophores Due to the large intermolecular interaction force in the polymer, the polarization efficiency is not high, and the electro-optical coefficient is small, which cannot well meet the requirements of deviceization.

Contents of the invention

The purpose of the present invention is to provide a molecular hyperpolarizability (β value) with ultra-high first order, good solubility, good film-forming properties after doping with polymers, easy to polarize, high macroscopic electro-optic coefficient, easy to device An organic second-order nonlinear optical chromophore with a D-π-A structure modified by a dendritic group; where D is an electron donor, π is a conjugated π electron bridge, and A is an electron acceptor.

Another object of the present invention is to provide a method for synthesizing an organic second-order nonlinear optical chromophore with a D-π-A structure modified by a dendritic group.

Another object of the present invention is to provide a use of an organic second-order nonlinear optical chromophore with a D-π-A structure modified by a dendritic group.

The organic second-order nonlinear optical chromophore with D-π-A structure modified by dendritic group of the present invention has the following structure:

D in the D-π-A structure is a 4-(NR ₁ , NR ₂ ) aminobenzene electron donor, π is a 3,4-diR _{3oxythiophene} conjugated electron bridge, and A is a three Cyanopyrroline (TCP) electron acceptor, the hydrogen atom on the acceptor nitrogen atom is replaced by a dendritic 3,5-diR ₄ oxybenzyl group.

Wherein, R ₁ and R ₂ are respectively or simultaneously alkyl, silane-protected hydroxyalkyl or one of hydroxyalkyl; R ₃ is alkyl; R ₄ is alkyl, acyl, benzyl, anthracenbenzyl or One of naphthylbenzyl and the like.

The carbon chain length in the alkyl group is 1-20 carbon atoms.

Chromophores with aniline-type electron donors, thiophene-type conjugated electron bridges and tricyanopyrroline (TCP)-type electron acceptors have high first-order molecular hyperpolarizability. The steric hindrance group contained on the conjugated electron bridge and the introduction of dendritic modification groups on the electron acceptor can increase the distance between the chromophore molecules, reduce the interaction force between the chromophore molecules, and reduce the The probability of molecular aggregation improves the polarization efficiency and thus the overall electro-optic coefficient of the material; in addition, if the flexible chain is used, the solubility of the chromophore in the solvent and the compatibility with the polymer can be improved, which is beneficial to the preparation of the device.

The synthetic method of the organic second-order nonlinear optical chromophore with D-π-A structure modified by dendritic group of the present invention comprises the following steps:

1) Bromo-3,4-diR _3oxythienyl triphenylphosphine, 4-(NR ₁ , NR ₂ )aminobenzaldehyde electron donor and sodium hydride are mixed in anhydrous ether solvent, Stir at a temperature of 20-50°C for 18-50 hours, pour the reaction product into ice water, separate the liquids, extract the water phase with ether, combine the organic phases, dry the organic phases with anhydrous magnesium sulfate, filter, and remove the ether by rotary evaporation. Chromatographic separation gave 4-(NR ₁ , NR ₂ )aminostyrene- _3,4 -diR 3oxythiophene, wherein bromo-3,4-diR _{3oxythienyltriphenylphosphine} : The molar ratio of 4-(NR ₁ , NR ₂ ) aminobenzaldehyde electron donor: sodium hydride is 1:1:15-30;

Wherein, R ₁ and R ₂ are respectively or simultaneously an alkyl group or one of acetyl-protected hydroxyalkyl groups, and R ₃ is an alkyl group;

2) Mix the 4-(NR ₁ , NR ₂ )aminostyrene-3,4-diR _{3oxythiophene} obtained in step 1) with phosphorus oxychloride and N,N-dimethylformamide solvent at 0°C After mixing at low temperature, react at a temperature of 70-110°C for 2-5 hours, cool down after the reaction, pour into an aqueous solution of sodium carbonate, extract the water phase with ether, separate the liquids, combine the organic phases, and wash the organic phases with saturated brine. Separate the liquid, dry the organic phase with anhydrous magnesium sulfate, filter, remove the ether by rotary evaporation, and separate by column chromatography to obtain 4-(NR ₁ , NR ₂ )aminostyrene-3,4-diR _{3oxythiophenecarbaldehyde} , wherein , 4-(NR ₁ , NR ₂ )aminostyrene-3,4-diR _{3oxythiophene} : The molar ratio of phosphorus oxychloride is 1:1～1.2;

Wherein, R ₁ and R ₂ are respectively or simultaneously an alkyl group or one of hydroxyalkyl groups protected by an acetyl group; R ₃ is an alkyl group;

3) Dissolve the 4-(NR ₁ , NR ₂ )aminostyrene-3,4-diR _{3oxythiophene} carboxaldehyde and tricyanopyrroline electron acceptor obtained in step 2) in ethanol at a temperature of 40 React at ~70°C for 30-60 minutes, remove ethanol by rotary evaporation, and separate by column chromatography to obtain a chromophore with a structure of D-π-A, which can be further purified; among them, 4-(NR ₁ , NR ₂ )aminostyrene -3,4-two R ₃ oxythiophene carboxaldehyde: the molar ratio of tricyanopyrroline electron acceptor is 1: 3～6;

R ₁ and R ₂ in 4-(NR ₁ , NR ₂ )aminostyrene-3,4-diR _3- oxythiophene carboxaldehyde are respectively or simultaneously one of alkyl groups or hydroxyalkyl groups protected by acetyl groups ; R ₃ is an alkyl group;

Among them: D in the D-π-A structure is a 4-(NR ₁ , NR ₂ ) aminobenzene electron donor, π is a 3,4-diR _{3oxythiophene} conjugated electron bridge, and A is tricyano Pyrroline electron acceptors;

R ₁ and R ₂ in the 4-(NR ₁ , NR ₂ ) aminobenzene electron donor are respectively or simultaneously alkyl or silane-protected hydroxyalkyl groups;

3, R ₃ in the 4-diR ₃ oxythiophene conjugated electron bridge is an alkyl group;

R ₁ and R ₂ in the 4-(NR ₁ , NR ₂ ) aminobenzene electron donor are respectively or simultaneously silane-protected hydroxyalkyl groups, when 4-(NR ₁ , NR ₂ ) aminostyrene When R ₁ and R ₂ in -3,4-diR _{3oxythiophenecarbaldehyde} are respectively or simultaneously acetyl-protected hydroxyalkyl groups, 4-(NR ₁ , NR ₂ )aminostyrene-3,4-di Before the reaction of R _{3oxythiophene} carboxaldehyde with tricyanopyrroline electron acceptor, the acetyl group protection needs to be removed, and then the hydroxyalkyl group is protected with silane to obtain 4-(NR ₁ , NR ₂ )amino with silane protection Styrene-3,4- _{diR3oxythiophenecarbaldehyde} ;

4) the chromophore of the D-π-A structure synthesized in step 3) and the dendritic 3,5-two R ₄ oxybenzyl halides and potassium carbonate are dissolved in acetonitrile in a molar ratio of 1:1:1, and the React at a temperature of 50-80°C for 1-10 hours, wash with water, extract the aqueous phase with ether, separate the liquids, combine the organic phases, dry the organic phases with anhydrous magnesium sulfate, and separate by column chromatography to generate dendrimer modified with D-π -The organic second-order nonlinear optical chromophore of A structure, the structure is:

Wherein, R ₁ and R ₂ are respectively or simultaneously one of alkyl, hydroxyalkyl or silane-protected hydroxyalkyl; R ₃ is alkyl; R ₄ is alkyl, acyl, benzyl, anthracenbenzyl or One of naphthylbenzyl and the like.

The carbon chain length in the alkyl group is 1-20 carbon atoms.

The reactant 4-(NR ₁ , NR ₂ ) aminobenzaldehyde electron donor described in step 1), wherein R ₁ and/or R ₂ is a hydroxyalkyl group, the hydroxyalkyl group needs to use an acetyl group before the reaction protection, the specific scheme is as the technical scheme known to those skilled in the art: 4-(NR ₁ , NR ₂ ) aminobenzaldehyde electron donor and acetic anhydride are dissolved in pyridine, heated to reflux under N ₂ protection (generally about 2 hours), the 4-(NR ₁ , NR ₂ ) aminobenzaldehyde electron donor with acetyl-protected hydroxyalkyl groups can be obtained, wherein, R ₁ , the total moles of hydroxyl groups in R ₂ : acetic anhydride The number of moles is 1:1.

Step 3) The removal of the protection of the acetyl group, the specific scheme is as the technical scheme known to those skilled in the art: the 4-(NR ₁ , NR ₂ )aminostyrene-3,4-di R _{3oxythiophene} carboxaldehyde is mixed with potassium carbonate aqueous solution and methanol, and reacted at 70°C (generally about 10 hours), so as to remove the acetyl protecting group. Among them, the acetyl-protected 4-(NR ₁ , NR ₂ ) The molar ratio of aminostyrene-3,4-diR _{3oxythiophene} carboxaldehyde:potassium carbonate is 1:6.

The silane-protected hydroxyalkyl group in step 3) is prepared by dissolving 4-(NR ₁ , NR ₂ )aminostyrene-3,4-diR _{3oxythiophenecarbaldehyde} , tert-butyldimethylsilyl chloride and imidazole in In N,N-dimethylformamide (DMF), stir (generally about 24 hours) to obtain 4-(NR ₁ , NR ₂ )aminostyrene-3,4-diR ₃ with silane protection Oxythiophene carboxaldehyde, wherein the total moles of hydroxyl groups in R ₁ and R ₂ : the moles of tert-butyldimethylchlorosilane: the moles of imidazole are 1:1:1.

When R ₁ and R ₂ in the organic second-order nonlinear optical chromophore with D-π-A structure modified by the dendritic group obtained in step 4) are respectively or simultaneously silane-protected hydroxyalkyl groups, the removal After the silane protecting group, an organic second-order nonlinear optical chromophore with a D-π-A structure is obtained modified by a dendritic group in which R ₁ and R ₂ are respectively or simultaneously hydroxyalkyl groups.

The removal of the silane protecting group is to dissolve the organic second-order nonlinear optical chromophore with the D-π-A structure modified by the silane-protected dendritic group in acetone, and drop a catalytic amount of hydrochloric acid , stirring at room temperature (generally about 3 hours) can remove the protecting group.

The column chromatographic separation of described step 1), step 2), step 3) and step 4): the stationary phase is 200～300 mesh silica gel, the mobile phase is the mixed solution of sherwood oil and acetone, the volume ratio of sherwood oil: acetone It is 3:1.

The organic second-order nonlinear optical chromophore with D-π-A structure modified by dendritic group of the present invention is doped with polymers such as amorphous polycarbonate or polymethyl methacrylate (mass ratio is 1: 1-100) Polarized polymers can be prepared, and the prepared polarized polymers can be stretched into films and used as materials in integrated optics or optoelectronics.

The advantages of the present invention are:

1) The organic second-order nonlinear optical chromophore with D-π-A structure modified by the dendritic group of the present invention has a strong electron-withdrawing ability due to the introduction of a thiophene ring conjugated π-electron bridge with strong electron transport ability For the tricyanopyrroline acceptor, the first-order molecular hyperpolarizability of the chromophore molecule is greatly enhanced.

2) The organic second-order nonlinear optical chromophore with D-π-A structure modified by the dendritic group of the present invention, the ether bond-linked branch and acceptor on the 3 and 4 positions of the thiophene electronic bridge The introduction of the terminal dendritic modification group improves the solubility and film-forming properties of the chromophore in the polymer, reduces the interaction force between molecules, and improves the polarization efficiency of the molecule. The dendritic group of the present invention When the modified organic second-order nonlinear optical chromophore with D-π-A structure is doped with amorphous polycarbonate or polymethyl methacrylate at a mass ratio of 1:10, the obtained polarized polymer material The electro-optic coefficient can reach 217pm/V, much higher than the reported traditional D-π-A structure chromophore.

3) The organic second-order nonlinear optical chromophore with D-π-A structure modified by the dendritic group of the present invention can introduce cross-linkable groups at the donor and acceptor ends, thereby greatly improving The orientation stability of the chromophore in the polymer improves the service life of the material and meets the requirements of the device.

Detailed ways

Example 1

Synthesis of dendrimer-modified chromophores with D-π-A structure as shown below

The synthetic route is as follows:

Wherein, Me is a methyl group, PPh is _{triphenylphosphine} , TBDMSCl is tert-butyldimethylsilyl chloride, and TCP is a tricyanopyrroline electron acceptor, and its structure is:

The synthesis method is:

1) Synthesis of Compound 2

Get 4g (0.0064mol) bromo-3,4-dihexyloxythienyltriphenylphosphine, 1.9g (0.0064mol) acetyl protected 4-(N,N-dihydroxyethyl)aminobenzaldehyde Electron donor, 4.6g (0.192mol) sodium hydride (NaH) mixed in 100ml of anhydrous ether solvent, stirred at 50 ° C for 18 hours, the reaction product was poured into 200ml of ice water, separated, ether extracted the water phase, combined The organic phase was dried with anhydrous magnesium sulfate, filtered, and the ether was removed by rotary evaporation to obtain a brown-red viscous substance, which was separated by column chromatography to obtain pure acetyl-protected compound 2 product (the stationary phase was 200-300 mesh silica gel, mobile The phase is a mixture of petroleum ether and acetone, the volume ratio of petroleum ether: acetone is 3:1) 3.1 g, and the yield is 86%.

MS, m/z: 573 (M ⁺ ); ¹ H NMR (400 MHz; CDCl ₃ ), δ: 7.35 (d, 2H), 7.06 (d, 1H), 6.76 (d, 1H), 6.73 (d, 2H ), 5.95(s, 1H), 4.25(t, 4H), 4.05(t, 2H), 3.94(t, 2H), 3.64(t, 4H), 2.06(s, 6H), 1.76(m, 4H) , 1.48 (m, 4H), 1.34 (m, 8H), 0.91 (m, 6H).

2) Synthesis of compound 3

After mixing 0.8ml (0.0087mol) phosphorus oxychloride (POCl ₃ ), 5g (0.0087mol) acetyl-protected compound 2 and 15ml N, N-dimethylformamide (DMF) at 0°C, the temperature was raised at 70 React at ℃ for 5 hours, cool down after the reaction, pour into a solution made of _2gNa2CO3 and _80ml water, extract the aqueous phase three times with ether, separate the liquids, combine the organic phases, wash the organic phases with saturated brine, and separate the liquids. Dry the organic phase with anhydrous magnesium sulfate, filter, and remove the ether by rotary evaporation to obtain an orange-red sticky substance, which is separated by column chromatography (the stationary phase is 200-300 mesh silica gel, the mobile phase is a mixture of petroleum ether and acetone, petroleum ether: The volume ratio of acetone was 3:1), and 2.8 g of pure acetyl-protected compound 3 was obtained with a yield of 54%. MS, m/z: 601 (M ⁺ ); ¹ H NMR (400 MHz, CDCl ₃ ), δ: 9.91 (s, 1H), 7.39 (d, 2H), 7.24 (d, 1H), 7.02 (d, 1H ), 6.79(d, 2H), 4.28(t, 4H), 3.98(m, 4H), 3.65(t, 4H), 2.08(s, 6H), 1.75(m, 4H), 1.46(m, 4H) , 1.37(m, 8H), 0.90(m, 6H).

3) Synthesis of compound 4

Mix 2.8g (0.0047mol) of acetyl-protected compound 3, 3.9g (0.0282mol) of anhydrous potassium carbonate, 50ml of water and 150ml of methanol, react at 70°C for 10 hours, remove methanol by rotary evaporation, and wash the mixture with saturated brine , extract the aqueous phase with ether, separate the liquids, combine the organic phases, dry the organic phases with anhydrous magnesium sulfate, filter, remove the ether by rotary evaporation, and separate by column chromatography (the stationary phase is 200-300 mesh silica gel, and the mobile phase is petroleum ether and acetone The mixed solution of petroleum ether: acetone was 1:1 by volume), and 2 g of the orange-red deacetylated compound 4 was obtained as a solid, with a yield of 85%.

4) Synthesis of Compound 5

0.9g (0.0017mol) deprotected compound 4, 0.23g (0.0034mol) imidazole and 0.5g (0.0034mol) tert-butyldimethylsilyl chloride (TBDMSCl) were dissolved in 40ml N,N-dimethyl In formamide (DMF), stir at room temperature for 24 hours, pour the mixture into 300ml of water, extract the aqueous phase with 200ml of ethyl acetate, separate the liquids, dry the organic phase with anhydrous magnesium sulfate, filter, and remove the solvent by rotary evaporation, column chromatography Separation (the stationary phase is 200-300 mesh silica gel, the mobile phase is a mixture of petroleum ether and acetone, the volume ratio of petroleum ether: acetone is 5:1), and 1 g of silane-protected compound 5 was obtained as a solid, with a yield of 80%.

5) Synthesis of D-π-A chromophore 6

0.5 g (0.00066 mol) of silane-protected compound 5 and 0.73 g (0.00396 mol) of tricyanopyrroline (TCP) electron acceptor were dissolved in ethanol and reacted at 70°C for 30 minutes. The ethanol was removed by rotary evaporation and separated by column chromatography. (The stationary phase is 200-300 mesh silica gel, the mobile phase is a mixture of petroleum ether and acetone, and the volume ratio of petroleum ether:acetone is 3:1), and 0.125 g of dark green compound 6 was obtained with a yield of 21%. UV-Vis (CH ₃ COCH ₃ ): λ _max = 796.5; MS (MALDI-TOF), m/z: 911 (M ⁺ ); ¹ H NMR (400MHz, CDCl ₃ ), δ: 8.39 (s, 1H) , 7.39(d, 2H), 7.08(m, 4H), 6.73(d, 2H), 4.35(t, 2H), 4.02(t, 2H), 3.79(t, 4H), 3.59(t, 4H), 1.79 (m, 4H), 1.49 (m, 4H), 1.35 (m, 8H), 0.92 (t, 6H), 0.85 (s, 18H), 0.15 (s, 12H).

6) Synthesis of target product 7

Dissolve 50mg (0.055mmol) of chromophore 6, 7.6mg (0.055mmol) of anhydrous potassium carbonate and 23mg (0.055mmol) of dendritic 3,5-dioctyloxybenzyl halide in acetonitrile, at 80°C The reaction was carried out for 1 hour. Wash with water, extract the aqueous phase with ether, separate liquids, combine the organic phases, dry the organic phases with anhydrous magnesium sulfate, and separate by column chromatography (the stationary phase is 200-300 mesh silica gel, the mobile phase is a mixture of petroleum ether and acetone, petroleum ether: The volume ratio of acetone is 3:1) to obtain 39 mg of pure product, the yield is 57%. UV-Vis (CH ₃ COCH ₃ ): λ _max = 826.5; MS (MALDI-TOF), m/z: 1260 (M ⁺ ); ¹ H NMR (400MHz, CDCl ₃ ), δ: 7.26 (d, 2H) , 6.52(m, 6H), 6.39(s, 3H), 4.41(m, 6H), 3.82(m, 12H), 1.71(m, 6H), 1.45(m, 8H), 1.32(m, 20H), 0.91 (m, 36H), 0.15 (s, 12H).

Example 2

Synthesis of dendrimer-modified chromophores with D-π-A structure as shown below

The synthetic route is as follows:

Among them, PPh ₃ is triphenylphosphine, TCP is tricyanopyrroline electron acceptor, and its structure is

The synthesis method is:

1) Synthesis of compound 2

Get 4g (0.0064mol) bromo-3,4-dihexyloxythienyltriphenylphosphine, 1.1g (0.0064mol) 4-(N,N-diethyl)aminobenzaldehyde electron donor, 2.3 g (0.096mol) of sodium hydride (NaH) was mixed in 100ml of anhydrous ether solvent, and after stirring at 20°C for 50 hours, the reaction product was poured into 200ml of ice water, separated, the aqueous phase was extracted with ether, the organic phase was combined, and Dry the organic phase with anhydrous magnesium sulfate, filter, and remove ether by rotary evaporation to obtain a red sticky substance, which is separated by column chromatography (stationary phase is 200-300 mesh silica gel, mobile phase is a mixture of petroleum ether and acetone, petroleum ether: acetone) The volume ratio was 3:1), and 2.4 g of pure compound 2 was obtained with a yield of 82%.

2) Synthesis of compound 3

1.1ml (0.012mol) of POCl ₃ , 4.6g (0.01mol) of compound 2 and 20ml of N,N-dimethylformamide (DMF) were mixed at 0°C, heated up, and reacted at 110°C for 2 hours. After the reaction Cool down, pour into a solution made of _2.5gNa2CO3 and 100ml water, extract the aqueous phase three times with _150ml ether, separate the liquids, combine the organic phases, wash the organic phases with saturated brine, separate the liquids, and wash with anhydrous magnesium sulfate Dry the organic phase, filter, and remove ether by rotary evaporation to obtain a red sticky substance, which is separated by column chromatography (the stationary phase is 200-300 mesh silica gel, the mobile phase is a mixed solution of petroleum ether and acetone, and the volume ratio of petroleum ether: acetone is 3 : 1), 3.4 g of pure compound 3 was obtained with a yield of 70%.

3) Synthesis of D-π-A chromophore 4

1.1g (0.0023mol) of compound 3 and 1.27g (0.0069mol) of tricyanopyrroline (TCP) electron acceptor were dissolved in ethanol, reacted at 40°C for 60 minutes, rotary evaporation removed ethanol, and column chromatography (stationary phase 200-300 mesh silica gel, the mobile phase is a mixture of petroleum ether and acetone, the volume ratio of petroleum ether: acetone is 3:1), and 0.6 g of green compound 4 was obtained as a solid with a yield of 40%.

4) Synthesis of target product 5

Dissolve 55mg (0.084mmol) of chromophore 4, 32mg (0.084mmol) of dendritic 3,5-dibenzyloxybenzyl halide and 11.6mg (0.084mmol) of anhydrous potassium carbonate in acetonitrile, and react at 50°C 10 hours. Wash with water, extract the aqueous phase with ether, separate liquids, combine the organic phases, dry the organic phases with anhydrous magnesium sulfate, and separate by column chromatography (the stationary phase is 200-300 mesh silica gel, the mobile phase is a mixture of petroleum ether and acetone, petroleum ether: The volume ratio of acetone was 3:1), and 52 mg of pure product was obtained with a yield of 65%. m/z: 953 (M ⁺ ); ¹ H NMR (400MHz, CDCl ₃ ), δ: 7.32 (m, 12H), 6.61 (m, 6H), 6.24 (s, 3H) 5.39 (s, 4.31 (s, 2H), 3.69 (m, 84H), H), 1.71 (m, 4H), 1.32 (m, 12H), 0.98 (m, 12H).

Example 3

Synthesis of dendrimer-modified chromophores with D-π-A structure as shown below

The synthetic route is as follows:

Among them, Me is a methyl group, PPh ₃ is triphenylphosphine, TBDMSCl is tert-butyldimethylsilyl chloride, and TCP is a tricyanopyrroline electron acceptor, and its structure is

The synthesis method is:

1) Synthesis of compound 2

Take 4g (0.0068mol) of bromo-3,4-dibutoxythienyltriphenylphosphine, 1.5g (0.0068mol) of acetyl-protected 4-(N-methyl, N-hydroxyethyl)amino Benzaldehyde electron donor and 4.1g (0.17mol) sodium hydride (NaH) were mixed in 100ml of anhydrous ether solvent, stirred at 40°C for 24 hours, the reaction product was poured into 200ml of ice water, separated, and the aqueous phase was extracted with ether , combine the organic phases, dry the organic phases with anhydrous magnesium sulfate, filter, and remove ether by rotary evaporation to obtain a brown-red viscous substance, which is separated by column chromatography to obtain pure acetyl-protected compound 2 products (the stationary phase is 200-300 mesh silica gel , mobile phase is the mixed liquid of sherwood oil and acetone, sherwood oil: the volume ratio of acetone is 3: 1) 2.6g, productive rate 85%.

2) Synthesis of compound 3

1ml (0.011mol) of phosphorus oxychloride (POCl ₃ ), 4.9g (0.011mol) of acetyl-protected compound 2 and 15ml of N,N-dimethylformamide (DMF) were mixed at 0°C, and the temperature was raised at 70 React at ℃ for 5 hours, cool down after the reaction, pour into a solution made of _2gNa2CO3 and _80ml water, extract the aqueous phase three times with ether, separate the liquids, combine the organic phases, wash the organic phases with saturated brine, and separate the liquids. Dry the organic phase with anhydrous magnesium sulfate, filter, and remove the ether by rotary evaporation to obtain an orange-red sticky substance, which is separated by column chromatography (the stationary phase is 200-300 mesh silica gel, the mobile phase is a mixture of petroleum ether and acetone, petroleum ether: The volume ratio of acetone is 3:1), and 3.1 g of acetyl-protected compound 3 was obtained with a yield of 60%.

3) Synthesis of compound 4

Mix 3.1g (0.0066mol) of acetyl-protected compound 3, 5.5g (0.0396mol) of anhydrous potassium carbonate, 50ml of water and 150ml of methanol, react at 70°C for 10 hours, remove methanol by rotary evaporation, and wash the mixture with saturated brine , extract the aqueous phase with ether, separate the liquids, combine the organic phases, dry the organic phases with anhydrous magnesium sulfate, filter, remove the ether by rotary evaporation, and separate by column chromatography (the stationary phase is 200-300 mesh silica gel, and the mobile phase is petroleum ether and acetone The mixed solution of petroleum ether: acetone was 1:1 by volume), and 2 g of the orange-red deacetylated compound 4 solid was obtained, with a yield of 83%.

4) Synthesis of Compound 5

1g (0.0023mol) deprotected compound 4, 0.16g (0.0023mol) imidazole and 0.35g (0.0023mol) tert-butyldimethylsilyl chloride (TBDMSCl) were dissolved in 40ml N, N-dimethylformaldehyde In amide (DMF), stir at room temperature for 24 hours, pour the mixture into 300ml of water, extract the aqueous phase with 200ml of ethyl acetate, separate the liquids, dry the organic phase with anhydrous magnesium sulfate, filter, remove the solvent by rotary evaporation, and separate by column chromatography (The stationary phase is 200-300 mesh silica gel, the mobile phase is a mixture of petroleum ether and acetone, and the volume ratio of petroleum ether:acetone is 5:1), and 1 g of silane-protected compound 5 was obtained as a solid with a yield of 82%.

5) Synthesis of D-π-A chromophore 6

0.5g (0.0009mol) silane-protected compound 5 and 0.83g (0.0045mol) tricyanopyrroline (TCP) electron acceptor were dissolved in ethanol, reacted at 60°C for 45 minutes, rotary evaporated to remove ethanol, and separated by column chromatography (The stationary phase is 200-300 mesh silica gel, the mobile phase is a mixture of petroleum ether and acetone, the volume ratio of petroleum ether:acetone is 3:1), and 0.16 g of silane-protected compound 6 was obtained as a green solid with a yield of 25%.

6) Synthesis of Compound 7

Dissolve 50mg (0.07mmol) of chromophore 6, 9.7mg (0.07mmol) of anhydrous potassium carbonate and 29mg (0.07mmol) of dendritic 3,5-dibenzoyloxybenzyl halide in acetonitrile, at 70°C The reaction was carried out for 3 hours. Wash with water, extract the aqueous phase with ether, separate liquids, combine the organic phases, dry the organic phases with anhydrous magnesium sulfate, and separate by column chromatography (the stationary phase is 200-300 mesh silica gel, the mobile phase is a mixture of petroleum ether and acetone, petroleum ether: The volume ratio of acetone is 3:1) to obtain 36 mg of silane-protected compound 7 as a solid, with a yield of 49%. m/z: 1041 (M ⁺ ).

7) Synthesis of target compound 8

Dissolve 36 mg of silane-protected compound 7 in 10 ml of acetone, drop 1 drop of hydrochloric acid with a dropper, stir at room temperature for 3 hours, remove acetone by rotary evaporation, and separate by column chromatography (stationary phase is 200-300 mesh silica gel, mobile phase is A mixture of petroleum ether and acetone (the volume ratio of petroleum ether: acetone is 1:1) to obtain 28 mg of the target compound 8 deprotected by silane as a solid, with a yield of 88%.

m/z: 927 (M ⁺ ); , 2H), 3.72 (m, 8H), 2.98 (s, 3H), 1.98 (s, 1H), 1.69 (m, 4H), 1.30 (m, 4H), 0.96 (m, 6H).

Example 4

film preparation

Add 0.1 g of polycarbonate (APC) into 1.00 ml of dibromomethane, stir for 3 to 5 hours until APC is completely dissolved, then add 0.010 g of the chromophore synthesized in Example 1 to obtain a mixed solution of chromophore and APC , on the ITO glass substrate with spin coating method coating. The rotational speed was controlled to be 500-1000 rpm, and the obtained film was dried in a vacuum drying oven at 60° C. for 24 hours. The thickness of the film is between 1.8 and 3.5 μm.

Example 5

Polarization and electro-optic coefficient measurement of the thin film prepared in embodiment 4

The film is polarized by the corona method, the polarization temperature is between 90-100°C, the polarization time is 10-30 minutes, the polarization voltage is controlled at about 9000-10000V, and the distance between the polarized electrode and the polymer film is 1 cm; the electro-optic coefficient (r ₃₃ ) was obtained by a simple reflection method (Simple Reflection Method, also known as the Teng-Man method, see Teng CC, Man HT, Simple reflection technique for measuring the electro-optic coefficient of poled polymers, Applied Physics Letters, 1990, 56(18), 1734-1736.) Determination. The highest measured electro-optic coefficient is 217pm/V.

Claims (5)

1. an organic second-order nonlinear optical chromophore with a D-π-A structure modified by a dendritic group, characterized in that: the organic second-order chromophore with a D-π-A structure modified by this dendritic group Nonlinear optical chromophores have the following structures:

D in the D-π-A structure is a 4-(NR ₁ , NR ₂ ) aminobenzene electron donor, π is a 3,4-diR _{3oxythiophene} conjugated electron bridge, and A is a three A cyanopyrroline electron acceptor, the hydrogen atom on the nitrogen atom of the acceptor is replaced by a dendritic 3,5- _{diR4oxybenzyl} group; Among them, R ₁ and R ₂ are one of alkyl, hydroxyalkyl or silane-protected hydroxyalkyl respectively or simultaneously; R ₃ is alkyl; R ₄ is alkyl, benzyl, anthracenbenzyl or naphthalenebenzyl one of the bases; The carbon chain length in the alkyl group is 1-20 carbon atoms. 2. a kind of synthetic method of the organic second-order nonlinear optical chromophore with D-π-A structure that dendrimers modify according to claim 1, it is characterized in that, the method comprises the following steps: 1) Bromo-3,4-diR _3oxythienyl triphenylphosphine, 4-(NR ₁ , NR ₂ )aminobenzaldehyde electron donor and sodium hydride are mixed in anhydrous ether solvent, Stir, pour the reaction product into ice water, separate liquids, extract the aqueous phase with ether, combine the organic phases, dry the organic phases, filter, remove the ether by rotary evaporation, and separate by column chromatography to obtain 4-(NR ₁ , NR ₂ )aminostyrene- 3,4-diR _{3oxythiophene} , wherein bromo-3,4-diR _3oxythienyl triphenylphosphine: 4-(NR ₁ , NR ₂ ) aminobenzaldehyde electron donor: The molar ratio of sodium hydride is 1:1:15～30; R ₁ and R ₂ are respectively or simultaneously an alkyl group or one of acetyl-protected hydroxyalkyl groups, and R ₃ is an alkyl group; 2) Mix the 4-(NR ₁ , NR ₂ )aminostyrene-3,4-diR _{3oxythiophene} obtained in step 1) with phosphorus oxychloride and N,N-dimethylformamide solvent at 0°C After mixing at low temperature, react at a temperature of 70-110°C, cool down after the reaction, pour into aqueous sodium carbonate solution, extract the aqueous phase with ether, separate the liquids, combine the organic phases, wash the organic phases with saturated brine, separate the liquids, and dry The organic phase was filtered, and diethyl ether was removed by rotary evaporation, and column chromatography was separated to obtain 4-(NR ₁ , NR ₂ )aminostyrene-3,4-diR _{3oxythiophenecarbaldehyde} , wherein, 4-(NR ₁ , NR ₂ ) aminostyrene-3,4-two R ₃ oxythiophene: the molar ratio of phosphorus oxychloride is 1: 1～1.2; R ₁ and R ₂ are respectively or simultaneously an alkyl group or one of acetyl-protected hydroxyalkyl groups; R ₃ is an alkyl group; 3) Dissolve the 4-(NR ₁ , NR ₂ )aminostyrene-3,4-diR _{3oxythiophene} formaldehyde and the tricyanopyrroline electron acceptor obtained in step 2) in ethanol at a temperature of 40 React at ~70°C for 30-60 minutes, remove ethanol by rotary evaporation, and separate by column chromatography to obtain a chromophore with a structure of D-π-A; among them, 4-(NR ₁ ,NR ₂ )aminostyrene-3,4- Two R ₃ oxythiophene formaldehyde: the mol ratio of tricyanopyrroline electron acceptor is 1: 3～6; R ₁ and R ₂ in 4-(NR ₁ , NR ₂ )aminostyrene-3,4-diR _3- oxythiophene carboxaldehyde are respectively or simultaneously one of alkyl groups or hydroxyalkyl groups protected by acetyl groups ; R ₃ is an alkyl group; Among them: D in the D-π-A structure is a 4-(NR ₁ , NR ₂ ) aminobenzene electron donor, π is a 3,4-diR _{3oxythiophene} conjugated electron bridge, and A is tricyano Pyrroline electron acceptors; R ₁ and R ₂ in the 4-(NR ₁ , NR ₂ ) aminobenzene electron donor are respectively or simultaneously alkyl or silane-protected hydroxyalkyl groups; 3, R ₃ in the 4-diR ₃ oxythiophene conjugated electron bridge is an alkyl group; R ₁ and R ₂ in the 4-(NR ₁ , NR ₂ ) aminobenzene electron donor are respectively or simultaneously silane-protected hydroxyalkyl groups, when 4-(NR ₁ , NR ₂ ) aminostyrene When R ₁ and R ₂ in -3,4-diR _{3oxythiophenecarbaldehyde} are respectively or simultaneously acetyl-protected hydroxyalkyl groups, 4-(NR ₁ , NR ₂ )aminostyrene-3,4-di Before the reaction between R _{3oxythiophene} carboxaldehyde and tricyanopyrroline electron acceptor, the acetyl group protection needs to be removed, and then the hydroxyalkyl group is protected with silane to obtain a 4-(NR ₁ , NR ₂ ) amino group with silane protection Styrene-3,4- _{diR3oxythiophenecarbaldehyde} ; 4) the chromophore of the D-π-A structure synthesized in step 3) and the dendritic 3,5-two R ₄ oxybenzyl halides and potassium carbonate are dissolved in acetonitrile in a molar ratio of 1:1:1, and the React at a temperature of 50-80°C, wash with water, extract the aqueous phase with ether, separate liquids, combine the organic phases, dry the organic phases, and separate by column chromatography to generate organic second-order non-organic compounds with D-π-A structure modified by dendritic groups. A linear optical chromophore with the structure:

Wherein, R ₁ and R ₂ are respectively or simultaneously one of alkyl, silane-protected hydroxyalkyl or hydroxyalkyl; R ₃ is an alkyl group; R ₄ is one of alkyl, benzyl, anthracene benzyl or naphthyl benzyl; When R ₁ and R ₂ in the organic second-order nonlinear optical chromophore with D-π-A structure modified by the dendritic group obtained in step 4) are respectively or simultaneously silane-protected hydroxyalkyl groups, the removal After the silane protecting group, the organic second-order nonlinear optical chromophore with D-π-A structure modified by R ₁ and R ₂ respectively or at the same time as hydroxyalkyl dendritic group; The carbon chain length in the alkyl group described in the above steps is 1-20 carbon atoms. 3. The application of the organic second-order nonlinear optical chromophore with D-π-A structure modified by dendritic group according to claim 1, characterized in that: the modified dendritic group The organic second-order nonlinear optical chromophore with D-π-A structure is doped with amorphous polycarbonate or polymethyl methacrylate to prepare polarized polymer, and used as a material in integrated optics or optoelectronics. 4. purposes according to claim 4, it is characterized in that: the organic second-order nonlinear optics chromophore with D-π-A structure of described dendritic group modification is the same as amorphous polycarbonate or polyformaldehyde The mass ratio of methyl acrylate doping is 1:1-100. 5. purposes according to claim 5, it is characterized in that: the organic second-order nonlinear optical chromophore with D-π-A structure of described dendritic group modification and amorphous polycarbonate or polyformaldehyde The mass ratio of methyl acrylate doping is 1:10.