CN100361990C - Second-order nonlinear optical chromophore containing indole group and its preparation method - Google Patents

Abstract

The invention relates to a second-order nonlinear optical chromophore containing indole groups, which has the following general formula: in the formula, R is various hydrocarbon groups, aromatic groups or other functional groups of heterocyclic compounds. X is an oxygen or sulfur atom, and A is a variety of electron-withdrawing acceptors, such as malononitrile, thiobarbituric acid, 3-phenyl-isoxazolone, 2-dicyanomethylene-3- Cyano-4,5,5-trimethyl-2,5-dihydrofuran, etc. In the present invention, through a series of chemical reactions, indole, halogenated hydrocarbons, various electron-withdrawing acceptors, bromofurylmethyltriphenylphosphine or 2-methylthiophene and other reagents can be used as raw materials to prepare indolyl-containing Group of second-order nonlinear optical chromophores. Second-order nonlinear optical chromophores containing indole groups, as second-order nonlinear optical materials, can be used in telecommunication, data storage, phase conjugation and other aspects.

Description

Second-order nonlinear optical chromophore containing indole group and its preparation method

technical field

The invention relates to a second-order nonlinear optical chromophore containing an indole group and a preparation method thereof.

Background technique

Information technology is developed on the basis of electronics and microelectronics technology, but due to the physical limits of electrons—including the transmission speed limit of electrons as information carriers (the maximum transmission speed of electrons is 600km/s) and components (functional units) The density limit formed by the mutual interference of electronic charges—"Moore's Law" cannot last forever, and the carrier level of electronic information technology can only be gigabits (Gb, that is, 10 ⁹ bits). On the other hand, the speed of photons is much faster than that of electrons, and its frequency is much higher than that of radio (such as microwaves). Using photons instead of electrons to transmit information can greatly speed up the processing speed of information and increase the capacity of processing information. Overcome the bottleneck of microelectronics technology, and transmit information more accurately, efficiently and over longer distances. For the development of all-optical information technology, nonlinear optics (NLO) is an indispensable key subject. It plays an extremely important role in practical fields such as high-speed optical communication, optical information processing and optoelectronics. Nonlinear optical materials play an important role in these fields. The application prospect of it has been paid more and more attention.

Compared with inorganic materials, organic polymer nonlinear optical materials have been widely valued due to their ultrafast response speed, large nonlinear optical response, high optical damage threshold, excellent processability and low dielectric constant. . In order to meet the practical requirements, these materials must not only have a large nonlinear optical response, but also meet the requirements of transparency, thermal stability and processability of the device. Due to the nonlinear optical response of polymer materials Both depend on the nonlinear optical properties of the nonlinear optically active group (often called chromophore) molecules, so the design and synthesis of a large molecular first-order hyperpolarizability (β) and good optical transparency Second-order nonlinear optical chromophore molecules have long been one of the most challenging topics.

The following are references relevant to the present invention: Moemer, W.E.; Jepsen, A.G.; Thompson, C.L.Annu.Rev.Mater.Sci.1997,32,585./ Ye Cheng; "Nonlinear Optical Properties of Organic Solids", " Organic Solids Chapter 5, edited by Zhu Daoben, Wang Fosong, Shanghai Science Press, 1999; p.181./Hua, J.; Luo, J.; Qin, J.; Shen, Y.; Zhang, Y.; Lu, Z.J. Mater.Chem.2002, 12, 863.

Contents of the invention

The object of the present invention is to provide a second-order nonlinear optical chromophore containing an indole group and a preparation method thereof. This type of chromophore has a large molecular first-order hyperpolarizability (β), good optical transparency, and high thermal stability, and can be used as a new type of second-order nonlinear optical material in telecommunication, data storage, and phase sharing. The yoke and other aspects have been practically applied.

The technical scheme provided by the invention is: a class of second-order nonlinear optical chromophores containing indole groups, which have the following general formula:

In the formula, R is various hydrocarbon groups, aromatic groups or other functional groups of heterocyclic compounds. X is an oxygen or sulfur atom, and A is a variety of electron-withdrawing acceptors, such as malononitrile, thiobarbituric acid, 3-phenyl-isoxazolone, 2-dicyanomethylene-3- Electron-withdrawing groups such as cyano-4,5,5-trimethyl-2,5-dihydrofuran.

The above R is a C ₁ -C ₉ alkane group or a C ₇ -C ₁₁ aromatic group.

The present invention also provides a method for preparing the above-mentioned second-order nonlinear optical chromophore, using indole and C ₁ -C ₉ halogenated alkanes or C ₇ -C ₁₁ halogenated aromatics as raw materials to prepare substituted indole A, wherein indole The molar ratio of indole and C ₁ -C ₉ halogenated alkanes or C ₇ -C ₁₁ halogenated aromatics is 1:1.0～2.0, and the substituted indole A is an alkane group with C ₁ -C ₉ or C on the N atom. Indole with ₇ -C ₁₁ aromatic group; substituted indole A reacts with N,N-dimethylformamide and phosphorus oxychloride to prepare indole aldehyde B, wherein substituted indole A, N,N-dimethyl The molar ratio of methyl formamide and phosphorus oxychloride is 1:1.1～1.9:1.1～1.9; then indolaldehyde B reacts with bromofurylmethyl triphenylphosphine or bromothiophenemethyl triphenylphosphine to prepare Vinyl indole furan C or vinyl indole thiophene D, wherein the molar ratio of indole aldehyde B to bromofurylmethyltriphenylphosphine or bromothienylmethyltriphenylphosphine is 1:1.0～2.0; ethylene Vinylindole furan C reacts with N, N-dimethylformamide and phosphorus oxychloride to prepare vinyl indole furan aldehyde E, wherein vinyl indole furan C, N, N-dimethylformamide, three The molar ratio of phosphorus oxychloride is 1: 1.1～1.9: 2.0～3.7; or vinylindolethiophene D reacts with n-butyllithium and N, N-dimethylformamide to prepare vinylindolethiophene aldehyde F, wherein The molar ratio of vinylindolethiophene D to n-butyllithium and N,N-dimethylformamide is 1:1.1～1.5:1.0～1.4; finally vinylindolefuran E or vinylindolethiophene Aldehyde F as raw material, with malononitrile, thiobarbituric acid, 3-phenyl-isoxazolone or 2-dicyanomethylene-3-cyano-4,5,5-trimethyl -2,5-dihydrofuran reaction to obtain a second-order nonlinear optical chromophore containing indole groups, wherein vinyl indole furan aldehyde E or vinyl indole thiophene aldehyde F and various electron-withdrawing groups The molar ratio between them is 1:1～1.3. .

The second-order nonlinear optical chromophore containing indole group of the present invention can be used as a second-order nonlinear optical material for practical application in remote communication, data storage, phase conjugation and the like.

The advantages of the present invention are:

1. The second-order nonlinear optical chromophore containing the indole group of the present invention has very good optical transparency. Compared with aniline analogs, its maximum absorption wavelength has been shifted by 20-30 nanometers, which is very rare .

2. The second-order nonlinear optical chromophore containing indole group of the present invention has very high second-order nonlinear optical performance (the first-order hyperpolarizability of eight chromophores in example 1 and example 2 is 1162 successively , 1540, 412, 615, 1068, 1108, 685, 597×10 ^-30 esu).

3. The present invention describes the preparation of second-order nonlinear optical chromophores containing indole groups, enriches the content of second-order nonlinear optical chromophore research, and expands second-order nonlinear optical chromophores to a certain extent The methods and design ideas of group forming chemistry.

Detailed ways

Example 1:

R is n-hexyl, and when X is an oxygen atom, the synthetic route is as follows:

A= in above-mentioned Ia, Ib, Ic, Id compound is respectively

The synthesis method is:

Synthesis of N-hexylindole (compound 1)

In a 250mL round bottom flask, put potassium hydroxide solid and N,N-dimethylformamide (3-10 times the mass of potassium hydroxide), stir for 20 minutes, add indole, and stir for 40 minutes. A solution of 1-bromo-n-hexane in N,N-dimethylformamide (mass percentage concentration between 20% and 50%) was added using a constant pressure funnel. Then the temperature was raised to 50°C, and the reaction was stirred for 2-20 hours. Pour the reaction solution into an appropriate amount of water, extract with chloroform, spin off the chloroform, and distill under reduced pressure with an oil pump to obtain a light yellow liquid, which is the product N-hexylindole. Wherein, the molar ratio of potassium hydroxide, indole and 1-bromo-n-hexane is 5:1:1.2.

Synthesis of 3-Formyl-N-hexylindole (Compound 2)

Weigh compound 1, dissolve it in a 100 mL flask with 1,2-dichloroethane (concentration ranges from 3% to 10% by mass), cool to 0°C in an ice bath, and stir. N,N-Dimethylformamide was added, followed by phosphorus oxychloride. Heated to reflux for 2 hours. After cooling, the reaction liquid was poured into water and extracted with chloroform. Chloroform was spin-off, and column chromatography was performed with chloroform as eluent to obtain a reddish-brown liquid product 3-formyl-N-hexylindole. The molar ratio of compound 1, N,N-dimethylformamide and phosphorus oxychloride is 1:1.3:1.3.

Synthesis of 2-(N-n-hexyl-3-vinylindole)furan (Compound 3)

Weigh bromofurylmethyltriphenylphosphine and place it in a Schlenk tube, under nitrogen protection, add anhydrous tetrahydrofuran (5-10 times the mass of bromofurylmethyltriphenylphosphine), add potassium tert-butoxide, 3-Formyl-N-hexylindole (compound 2) was then added. React for 20-30 hours. Pour the reaction solution into distilled water, extract with chloroform, spin off the chloroform, and use chloroform and petroleum ether in a ratio of 1:1 (volume ratio) as eluents for column chromatography to obtain bright yellow-green liquid 2-(N- n-hexyl-3-vinylindole)furan. Wherein, the molar ratio of bromofurylmethyltriphenylphosphine, potassium tert-butoxide and 3-formyl-N-hexylindole is 1:1.5:1.

Synthesis of 2-(N-n-hexyl-3-vinylindole)-5-formylfuran (Compound 4)

In a 100 mL two-necked flask, compound 3 was added and dissolved with 1,2-dichloroethane (mass percentage concentration between 3% and 10%). Add the mixture of phosphorus oxychloride and N,N-dimethylformamide into the above-mentioned two-necked flask. After stirring at room temperature for 2 h, the reaction solution was poured into saturated sodium carbonate solution and extracted with 1,2-dichloroethane. The 1,2-dichloroethane was spin-off, and column chromatography was performed with chloroform as eluent to obtain orange-red solid 2-(N-n-hexyl-3-vinylindole)-5-formylfuran. Wherein, the molar ratio of compound 3, phosphorus oxychloride and N,N-dimethylformamide is 1:1.4:2.4.

Synthesis of Chromophore Ia

The above-mentioned compound 4 was weighed and dissolved in a 100 mL flask with absolute ethanol (with a mass percentage concentration between 0.1% and 1%), malononitrile was added, and stirred to dissolve it. After reacting at room temperature for 2 h, the reaction liquid was removed from ethanol on a rotary evaporator, and then subjected to column chromatography, and the eluent was 1:1 (volume ratio) of chloroform and petroleum ether to obtain a red solid chromophore Ia. Wherein, the molar ratio of compound 4 and malononitrile is 1:1. Melting point: 95-96°C. IR: 2218 cm ^-1 (C≡N). UV-Vis (chloroform, λmax): 526 nm.

Synthesis of Chromophore Ib

The above-mentioned compound 4 was weighed, dissolved in a 100 mL flask with absolute ethanol (concentration of 0.1%-1% by mass), added thiobarbital, and heated to reflux for 3 hours. The ethanol was spinned off, and column chromatography was performed with chloroform and petroleum ether (boiling point 60°C-90°C) at a ratio of 1:1 (volume ratio) as eluents to obtain a blue-purple solid chromophore Ib. Wherein, the molar ratio of compound 4 and thiobarbital is 1:1. Melting point: 198-200°C. IR: 1665 cm ^-1 (C=O). UV-Vis (chloroform, λmax): 590 nm.

Synthesis of Chromophore Ic

The above-mentioned compound 4 was weighed and dissolved in a 100 mL flask with absolute ethanol (concentration ranged from 0.1% to 1% by mass), added 3-phenyl-isoxazolone and stirred to dissolve it. Stir at room temperature for 2 hours, spin off ethanol, and use chloroform as the eluent for column chromatography to obtain a blue-purple solid chromophore Ic. Wherein, the molar ratio of compound 4 and 3-phenyl-isoxazolone is 1:1.3. Melting point: 118-120°C. IR: 1665 cm ^-1 (C=O). UV-Vis (chloroform, λmax): 566 nm.

Synthesis of Chromophore Id

Weigh compound 4, dissolve it in a 100mL flask with absolute ethanol (mass percentage concentration is between 0.1%-1%), add 2-dicyanomethylene-3-cyano-4,5,5 - Trimethyl-2,5-dihydrofuran, heated to reflux for 3 hours. Stop the reaction, spin off ethanol, and perform column chromatography with chloroform:ethyl acetate=20:3 (volume ratio) as eluent to obtain dark blue-purple solid powder chromophore Id. Wherein, the molar ratio of compound 4 to 2-dicyanomethylene-3-cyano-4,5,5-trimethyl-2,5-dihydrofuran is 1:1.2. Melting point: 202-204°C. IR: 2223 cm ^-1 (C≡N). UV-Vis (chloroform, λmax): 650 nm.

Example 2:

R is n-hexyl, and when X is a sulfur atom, the synthetic route is as follows:

A= in the above-mentioned IIa, IIb, IIc, IId compound is respectively

The synthesis method is:

Preparation of Bromothiophenemethyltriphenylphosphine

Weigh 2-methylthiophene (5.01g, 50mmol), add in 250ml round bottom flask, then add carbon tetrachloride 150ml, NBS powder (10.7g, 60mmol), BPO powder 0.1g, be heated to _CCl Reflux 2h, The reaction solution gradually changed from light yellow solution to darker yellow. Filter the reaction solution and wash the _filter residue with _CCl4 , collect the resulting _CCl4 solution, spin off _CCl4 to obtain a yellow oily liquid, add water to it to remove water-soluble impurities, extract with _CHCl3 , add anhydrous _Na2SO4 to dry overnight . Na ₂ SO ₄ was filtered off, the resulting yellow solution was transferred to a -250ml flask, PPh ₃ (10.7g, 50mmol) and CHCl ₃ 100ml were added, heated and stirred until CHCl ₃ was refluxed, and the heating was stopped after 2 hours of reaction. During the reflux process, a large amount of white solid appeared on the wall of the bottle, and the color of the solution became lighter. Filtration and washing the product with a small amount of _CHCl3 gave the product bromothienyltriphenylphosphine as a white solid powder.

3-Formyl-N-hexylindole (Compound 2) was synthesized as described in Example 1.

Synthesis of 2-(N-n-hexyl-3-vinylindole)thiophene (Compound 5)

Add n-hexylindolaldehyde 2 and bromothienyltriphenylphosphine to a Schlenk tube. Under the protection of nitrogen, add anhydrous tetrahydrofuran (10 times the mass of n-hexyl indolaldehyde 2) to the Schlek tube, then add potassium tert-butoxide, stir and react at room temperature for 24 hours, pour the reaction solution into water, and use _CHCl3 as the extraction agent to extract , spin off CHCl ₃ , and carry out column chromatography with chloroform and petroleum ether at a ratio of 1:1 (volume ratio) as the eluent to obtain the orange-red oily liquid product 2-(N-n-hexyl-3-vinylind Indole) thiophene. Wherein, the molar ratio of compound 2, bromothiophenemethyltriphenylphosphine and potassium tert-butoxide is 1:1:2.

Synthesis of 2-(N-n-hexyl-3-vinylindole)-5-formylthiophene (compound 6)

Add 2-(N-n-hexyl-3-vinylindole)thiophene and dry tetrahydrofuran (50 times the mass of 2-(N-n-hexyl-3-vinylindole)thiophene) to a dry Schlenk tube, Add n-butyllithium solution (the solvent is n-hexane, the concentration is 2.5mol/L) in a -78°C liquid nitrogen bath under the protection of _N2 , and stir for 1.5 hours. Then the reaction solution was lifted into the air, N,N-dimethylformamide was added, and stirred overnight at room temperature. Water was added to the reaction liquid, and after stirring, it was extracted with CHCl ₃ . Column chromatography was performed with CHCl ₃ as eluent to obtain 2-(N-n-hexyl-3-vinylindole)-5-formylthiophene as a viscous brown solid. Wherein, the molar ratio of 2-(N-n-hexyl-3-vinylindole)thiophene, n-butyllithium and N,N-dimethylformamide is 1:1.2:1.1.

Synthesis of Chromophore IIa

Add compound 6 into a 100ml round bottom flask, and then add ethanol to dissolve it. Weigh malononitrile and add to the reaction solution, heat up to 80°C, and stir for 4 hours. The ethanol was spinned off, and column chromatography was performed with _CHCl3 as the eluent to obtain the purple-black microcrystalline chromophore IIa. Wherein, the molar ratio of compound 6 and malononitrile is 1:1. Melting point: 115-117°C. IR: 2218 cm ^-1 (C≡N). UV-Vis (chloroform, λmax): 524 nm.

Synthesis of Chromophore IIb

Add compound 6 into a 100ml round bottom flask, and then add ethanol to dissolve it. Weigh thiobarbital into the reaction solution, raise the temperature to 80°C, and stir for 4 hours. The ethanol was spinned off, and column chromatography was performed with _CHCl3 as the eluent to obtain the blue-purple microcrystalline chromophore IIb. Wherein, the molar ratio of compound 6 and thiobarbital is 1:1.3. Melting point: 191-193°C. IR: 1653 cm ^-1 (C=O). UV-Vis (chloroform, λmax): 586 nm.

Synthesis of Chromophore IIc

Add compound 6 into a 100ml round bottom flask, and then add ethanol to dissolve it. Weigh 3-phenylisoxazolone into the reaction solution, raise the temperature to 80° C., and stir for 4 hours. The ethanol was spinned off, and column chromatography was performed with _CHCl3 as eluent to obtain the blue-black microcrystalline chromophore IIc. Wherein, the molar ratio of compound 6 and 3-phenylisoxazolone is 1:1.2. Melting point: 139-140°C. IR: 1733 cm ^-1 (C=O). UV-Vis (chloroform, λmax): 561 nm.

Synthesis of Chromophore IId

Add compound 6 into a 100ml round bottom flask, and then add ethanol to dissolve it. Weigh 2-dicyanomethylene-3-cyano-4,5,5-trimethyl-2,5-dihydrofuran into the reaction solution, raise the temperature to 80°C, and stir for 4 hours. Ethanol was spinned off, and column chromatography was performed with a mixed solvent of CHCl3:ethyl acetate=20:3 (volume ratio) as eluent to obtain blue-black microcrystalline chromophore IId. Wherein, the molar ratio of compound 6 to 2-dicyanomethylene-3-cyano-4,5,5-trimethyl-2,5-dihydrofuran is 1:1. Melting point: 178-180°C. IR: 2225 cm ^-1 (C=N). UV-Vis (chloroform, λmax): 638 nm.

Example 3:

R is a n-butyl group, and when X is an oxygen atom, the synthetic route is as follows:

A=in the above-mentioned IIIa, IIIb, IIIc, IIId compounds are respectively

The synthesis method is:

Synthesis of N-butylindole (compound 7)

In a 250mL round bottom flask, put potassium hydroxide solid and N,N-dimethylformamide (3-10 times the mass of potassium hydroxide), stir for 20 minutes, add indole, and stir for 40 minutes. Add 1-bromo-n-butane solution (solvent is N,N-dimethylformamide, mass percentage concentration is between 20%-50%) by constant pressure dropping funnel. Then the temperature was raised to 50°C, and the reaction was stirred for 2-20 hours. Pour the reaction liquid into water, extract with chloroform, spin off the chloroform, and distill under reduced pressure with an oil pump to obtain a light yellow liquid, which is the product N-butylindole. Wherein, the molar ratio of potassium hydroxide, indole and 1-bromo-n-butane is 2:1:1.2.

Synthesis of 3-formyl-N-butylindole (Compound 8)

Compound 7 was weighed and dissolved in a 100 mL flask with 1,2-dichloroethane (concentration ranged from 3% to 10% by mass), cooled to 0° C. in an ice bath, and stirred. N,N-Dimethylformamide was added, followed by phosphorus oxychloride. Heated to reflux for 2 hours. After cooling, the reaction solution was poured into water and extracted with chloroform. Chloroform was spin-off, and column chromatography was performed with chloroform as eluent to obtain a reddish-brown liquid product. The molar ratio of compound 7, N,N-dimethylformamide, and phosphorus oxychloride is 1:1.3:1.5. Synthesis of 2-(N-n-butyl-3-vinylindole)furan (compound 9)

Weigh bromofurylmethyltriphenylphosphine, place it in a Schlenk tube, and add anhydrous tetrahydrofuran (5-10 times the mass of bromofurylmethyltriphenylphosphine) under nitrogen protection, add an appropriate amount of tert-butanol Potassium, before adding 3-formyl-N-butylindole. React for 20-30 hours. Pour the reaction solution into distilled water, extract with chloroform, spin off the chloroform, and use chloroform and petroleum ether with a ratio of 1:1 (volume ratio) as eluents for column chromatography to obtain bright yellow-green liquid 2-(N- n-Butyl-3-vinylindole) furan. Wherein, the molar ratio of bromofurylmethyltriphenylphosphine, potassium tert-butoxide and 3-formyl-N-butylindole is 1:1.5:1.

Synthesis of 2-(N-n-butyl-3-vinylindole)-5-formylfuran (compound 10)

In a 100 mL two-necked flask, compound 9 was added and dissolved with 1,2-dichloroethane (mass percentage concentration between 3% and 10%). Add the mixture of phosphorus oxychloride and N,N-dimethylformamide into the above-mentioned two-necked flask. After stirring at room temperature for 2 hours, the reaction solution was poured into saturated sodium carbonate solution and extracted with 1,2-dichloroethane. The 1,2-dichloroethane was spin-off, and column chromatography was performed with chloroform as eluent to obtain orange-red solid 2-(N-n-butyl-3-vinylindole)-5-formylfuran. Wherein, the molar ratio of compound 9, phosphorus oxychloride and N,N-dimethylformamide is 1:1.4:2.4.

Synthesis of Chromophore IIIa

Compound 10 was weighed and dissolved in a 100 mL flask with absolute ethanol (mass percentage concentration between 0.1% and 1%), malononitrile was added, and stirred to dissolve it. After reacting at room temperature for 2 hours, the reaction liquid was removed from ethanol on a rotary evaporator, and then subjected to column chromatography, the eluent was 1:1 (volume ratio) of chloroform and petroleum ether to obtain a red solid chromophore IIIa. Wherein, the molar ratio of compound 10 and malononitrile is 1:1. IR: 2219 cm ^-1 (C≡N). UV-Vis (chloroform, λmax): 527 nm.

Synthesis of Chromophore IIIb

Compound 10 was weighed and dissolved in a 100 mL flask with absolute ethanol (with a concentration of 0.1%-1% by mass), added with thiobarbital, and heated to reflux for 3 hours. The ethanol was spinned off, and column chromatography was performed with chloroform and petroleum ether (boiling point 60-90° C.) at a ratio of 1:1 (volume ratio) as eluents to obtain a blue-purple solid chromophore IIIb. Wherein, the molar ratio of compound 10 and thiobarbital is 1:1.3. IR: 1663 cm ^-1 (C=O). UV-Vis (chloroform, λmax): 5910 nm.

Synthesis of Chromophore IIIc

Compound 10 was weighed and dissolved in a 100 mL flask with absolute ethanol (concentration ranged from 0.1% to 1% by mass), added 3-phenyl-isoxazolone and stirred to dissolve it. Stir at room temperature for 2 hours, spin off ethanol, and use chloroform as the eluent for column chromatography to obtain a blue-purple solid chromophore IIIc. Wherein, the molar ratio of compound 10 and 3-phenyl-isoxazolone is 1:1.2. IR: 1667 cm ^-1 (C=0). UV-Vis (chloroform, λmax): 565 nm.

Synthesis of Chromophore IIId

Weigh compound 10, dissolve it in a 100mL flask with absolute ethanol (mass percentage concentration is between 0.1%-1%), add 2-dicyanomethylene-3-cyano-4,5,5 - Trimethyl-2,5-dihydrofuran, heated to reflux for 3 hours. Stop the reaction, spin off ethanol, and perform column chromatography with chloroform:ethyl acetate=20:3 (volume ratio) as the eluent to obtain dark blue-purple solid powder chromophore IIId. Wherein, the molar ratio of compound 10 to 2-dicyanomethylene-3-cyano-4,5,5-trimethyl-2,5-dihydrofuran is 1:1. IR: 2224 cm ^-1 (C≡N). UV-Vis (chloroform, λmax): 652 nm.

Example 4:

R is a n-butyl group, and when X is a sulfur atom, the synthetic route is as follows:

A= in above-mentioned IVa, IVb, IVc, IVd compound is respectively

The synthesis method is:

3-Formyl-N-butylindole (Compound 8) was synthesized as described in Example 3.

Synthesis of 2-(N-n-butyl-3-vinylindole)thiophene (compound 11)

Compound 8 and bromothienyltriphenylphosphine were added to a Schlenk tube. Under nitrogen protection, add anhydrous tetrahydrofuran (10 times the mass of compound 8) to the Schlek tube, then add potassium tert-butoxide, stir and react at room temperature for 24 hours, then pour the reaction solution into water, use _CHCl3 as the extraction agent, spin off CHCl ₃ , using chloroform and petroleum ether in a ratio of 1:1 (volume ratio) as the eluent for column chromatography, the orange-red oily liquid product 2-(N-n-butyl-3-vinylindole) was obtained Thiophene. Wherein, the molar ratio of compound 8, bromothienyltriphenylphosphine and potassium tert-butoxide is 1:1:2.

Synthesis of 2-(N-n-butyl-3-vinylindole)-5-formylthiophene (compound 12)

Add 2-(N-n-butyl-3-vinylindole)thiophene and 50 times the mass of dry THF (2-(N-n-butyl-3-vinylindole)thiophene to a dry Schlenk tube ), add n-butyllithium (n-hexane solution, 2.5mol/L) in a -78°C liquid nitrogen bath under the protection of _N2 , and stir for 1.5 hours. Then the reaction solution was lifted into the air, N,N-dimethylformamide was added, and stirred overnight at room temperature. Water was added to the reaction liquid, and after stirring, it was extracted with CHCl ₃ . Column chromatography was performed with CHCl ₃ as eluent to obtain viscous brown solid compound 12. Wherein, the molar ratio of 2-(N-n-butyl-3-vinylindole)thiophene, n-butyllithium and N,N-dimethylformamide is 1:1.2:1.1.

Synthesis of Chromophore IVa

Add compound 12 into a 100ml round bottom flask, and then add ethanol to dissolve it. Weigh malononitrile and add to the reaction solution, heat up to 80°C, and stir for 4 hours. The ethanol was spinned off, and column chromatography was performed with _CHCl3 as the eluent to obtain purple-black microcrystalline chromophore IVa. Wherein, the molar ratio of compound 12 and malononitrile is 1:1. IR: 2217 cm ^-1 (C≡N). UV-Vis (chloroform, λmax): 523 nm.

Synthesis of Chromophore IVb

Add compound 12 into a 100ml round bottom flask, and then add ethanol to dissolve it. Weigh thiobarbital into the reaction solution, raise the temperature to 80°C, and stir for 4 hours. The ethanol was spinned off, and column chromatography was performed with _CHCl3 as the eluent to obtain blue-purple microcrystalline chromophore IVb. Wherein, the molar ratio of compound 12 and thiobarbital is 1:1.3. IR: 1651 cm ^-1 (C=O). UV-Vis (chloroform, λmax): 585 nm

Synthesis of Chromophore IVc

Add compound 12 into a 100ml round bottom flask, and then add ethanol to dissolve it. Weigh 3-phenylisoxazolone into the reaction solution, raise the temperature to 80° C., and stir for 4 hours. The ethanol was spinned off, and column chromatography was performed with _CHCl3 as the eluent to obtain the blue-black microcrystalline chromophore IVc. Wherein, the molar ratio of compound 12 and 3-phenylisoxazolone is 1:1.1. IR: 1731 cm ^-1 (C=O). UV-Vis (chloroform, λmax): 560 nm.

Synthesis of chromophore IVd

Add compound 12 into -100ml round bottom flask, then add ethanol to dissolve. Weigh 2-dicyanomethylene-3-cyano-4,5,5-trimethyl-2,5-dihydrofuran into the reaction solution, raise the temperature to 80°C, and stir for 4 hours. Ethanol was removed by spin, and column chromatography was performed with a mixed solvent of CHCl ₃ : ethyl acetate = 20:3 (volume ratio) as eluent to obtain blue-black microcrystalline chromophore IVd. Wherein, the molar ratio of compound 12 to 2-dicyanomethylene-3-cyano-4,5,5-trimethyl-2,5-dihydrofuran is 1:1. IR: 2227 cm ^-1 (C≡N). UV-Vis (chloroform, λmax): 639 nm.

Example 5:

When R is a benzyl group and X is an oxygen atom, the synthetic route is as follows:

A= in above-mentioned Va, Vb, Vc, Vd compound is respectively

The synthesis method is:

Synthesis of N-benzyl indole (compound 13)

In a 250mL round bottom flask, put potassium hydroxide solid and N,N-dimethylformamide (3-10 times the mass of potassium hydroxide), stir for 20 minutes, add indole, and stir for 40 minutes. A solution of benzyl chloride in N,N-dimethylformamide (mass percentage concentration between 20% and 50%) is added through a constant pressure dropping funnel. Then the temperature was raised to 50°C, and the reaction was stirred for 2-20 hours. Pour the reaction solution into water, extract with chloroform, spin off the chloroform, and distill under reduced pressure with an oil pump to obtain a light yellow liquid, which is the product Compound 13. Wherein, the molar ratio of potassium hydroxide, indole and benzyl chloride is 4:1:1.2.

Synthesis of 3-Formyl-N-benzylindole (Compound 14)

Compound 13 was weighed and dissolved in a 100 mL flask with 1,2-dichloroethane (concentration ranged from 3% to 10% by mass), cooled to 0°C in an ice bath, and stirred. N,N-Dimethylformamide was added, followed by phosphorus oxychloride. Heated to reflux for 2 hours. After cooling, the reaction solution was poured into water and extracted with chloroform. Chloroform was spin-off, and column chromatography was performed with chloroform as eluent to obtain compound 14 as a reddish-brown liquid product. The molar ratio of compound 13, N,N-dimethylformamide and phosphorus oxychloride is 1:13:13.

Synthesis of 2-(N-Benzyl-3-vinylindole)furan (Compound 15)

Weigh bromofurylmethyltriphenylphosphine, place it in a Schlenk tube, under nitrogen protection, add anhydrous tetrahydrofuran (5-10 times the mass of bromofurylmethyltriphenylphosphine), add potassium tert-butoxide , and then 3-formyl-N-benzylindole was added. React for 20-30 hours. The reaction solution was poured into distilled water, extracted with chloroform, the chloroform was spinned off, and column chromatography was performed with chloroform and petroleum ether in a ratio of 1:1 (volume ratio) as eluents to obtain bright yellow-green liquid Compound 15. Wherein, the molar ratio of bromofurylmethyltriphenylphosphine, potassium tert-butoxide and 3-formyl-N-benzyl indole is 1:1.5:1.

Synthesis of 2-(N-Benzyl-3-vinylindole)-5-formylfuran (compound 16)

In a 100 mL two-necked flask, compound 15 was added and dissolved with 1,2-dichloroethane (mass percentage concentration between 3% and 10%). Add the mixture of phosphorus oxychloride and N,N-dimethylformamide into the above-mentioned two-necked flask. After stirring at room temperature for 2 hours, the reaction solution was poured into saturated sodium carbonate solution and extracted with 1,2-dichloroethane. The 1,2-dichloroethane was spin-off, and column chromatography was performed with chloroform as eluent to obtain compound 16 as an orange-red solid. Wherein, the molar ratio of compound 15, phosphorus oxychloride and N,N-dimethylformamide is 1:1.4:2.4.

Synthesis of Chromophore Va

Compound 16 was weighed and dissolved in a 100 mL flask with absolute ethanol (mass percentage concentration between 0.1% and 1%), malononitrile was added, and stirred to dissolve it. After reacting at room temperature for 2 hours, the ethanol was removed from the reaction solution on a rotary evaporator, and then subjected to column chromatography, the eluent was 1:1 (volume ratio) of chloroform and petroleum ether to obtain a red solid chromophore Va. Wherein, the molar ratio of compound 16 and malononitrile is 1:1.3. IR: 2219 cm ^-1 (C≡N). UV-Vis (chloroform, λmax): 527 nm. Synthesis of Chromophore Vb

Compound 16 was weighed and dissolved in a 100 mL flask with absolute ethanol (0.1%-1% by mass concentration), added with thiobarbital, and heated to reflux for 3 hours. The ethanol was spinned off, and column chromatography was performed with chloroform and petroleum ether (boiling point 60-90° C.) at a ratio of 1:1 (volume ratio) as eluents to obtain a blue-purple solid chromophore Vb. Wherein, the molar ratio of compound 16 and thiobarbital is 1:1.3. IR: 1664cm ^-1 (C=O). UV-Vis (chloroform, λmax): 591 nm.

Synthesis of chromophore Vc

Compound 16 was weighed and dissolved in a 100 mL flask with absolute ethanol (with a concentration of 0.1%-1% by mass), added 3-phenyl-isoxazolone, and stirred to dissolve it. Stir at room temperature for 2 hours, spin off ethanol, and use chloroform as eluent for column chromatography to obtain blue-purple solid chromophore Vc. Wherein, the molar ratio of compound 16 and 3-phenyl-isoxazolone is 1:1. IR: 1665 cm ^-1 (C=O). UV-Vis (chloroform, λmax): 566 nm.

Synthesis of chromophore Vd

Weigh compound 16, dissolve it in a 100mL flask with absolute ethanol (mass percentage concentration between 0.1%-1%), add an appropriate amount of 2-dicyanomethylene-3-cyano-4,5 to it, 5-trimethyl-2,5-dihydrofuran, heated to reflux for 3 hours. Stop the reaction, spin off ethanol, and perform column chromatography with chloroform:ethyl acetate=20:3 (volume ratio) as the eluent to obtain dark blue-purple solid powder chromophore Vd. Wherein, the molar ratio of compound 16 to 2-dicyanomethylene-3-cyano-4,5,5-trimethyl-2,5-dihydrofuran is 1:1.3. IR: 2221 cm ^-1 (C≡N). UV-Vis (chloroform, λmax): 651 nm.

Embodiment 6:

When R is a benzyl group and X is a sulfur atom, the synthetic route is as follows:

A= in above-mentioned VIa, VIb, VIc, VId compound is respectively

The synthesis method is:

3-Formyl-N-benzylindole (Compound 14) was synthesized as described in Example 5.

Synthesis of 2-(N-Benzyl-3-vinylindole)thiophene (Compound 17)

Compound 14 and bromothienyltriphenylphosphine were added to a Schlenk tube. Under nitrogen protection, add anhydrous tetrahydrofuran (10 times the mass of compound 14) to the Schlek tube, then add potassium tert-butoxide, stir and react at room temperature for 24 hours, then pour the reaction solution into water, use _CHCl3 as the extraction agent, spin off CHCl ₃ was subjected to column chromatography using chloroform and petroleum ether at a ratio of 1:1 (volume ratio) as eluents to obtain compound 17 as an orange-red oily liquid product. Wherein, the molar ratio of compound 14, bromothienyltriphenylphosphine and potassium tert-butoxide is 1:1:2.

Synthesis of 2-(N-Benzyl-3-vinylindole)-5-formylthiophene (compound 18)

Add 2-(N-benzyl-3-vinylindole)thiophene and dry tetrahydrofuran (50 times the mass of 2-(N-benzyl-3-vinylindole)thiophene) to a dry Schlenk tube , under the protection of N ₂ , added n-butyllithium (n-hexane solution, 2.5mol/L) in a -78°C liquid nitrogen bath, and stirred for 1.5 hours. Then the reaction solution was lifted into the air, N,N-dimethylformamide was added, and stirred overnight at room temperature. Water was added to the reaction liquid, and after stirring, it was extracted with CHCl ₃ . Column chromatography was performed with CHCl ₃ as the eluent to obtain viscous brown solid compound 18. Wherein, the molar ratio of 2-(N-benzyl-3-vinylindole)thiophene, n-butyllithium and N,N-dimethylformamide is 1:1.2:1.1.

Synthesis of Chromophore VIa

Add compound 18 into a 100ml round bottom flask, and then add ethanol to dissolve it. Weigh malononitrile and add to the reaction solution, heat up to 80°C, and stir for 4 hours. The ethanol was spinned off, and column chromatography was performed with _CHCl3 as the eluent to obtain purple-black microcrystalline chromophore VIa. Wherein, the molar ratio of compound 18 and malononitrile is 1:1. IR: 2220 cm ^-1 (C≡N). UV-Vis (chloroform, λmax): 524 nm.

Synthesis of Chromophore VIb

Add compound 18 into a 100ml round bottom flask, and then add ethanol to dissolve it. Weigh thiobarbital into the reaction solution, raise the temperature to 80°C, and stir for 4 hours. The ethanol was spinned off, and column chromatography was performed with _CHCl3 as the eluent to obtain the blue-purple microcrystalline chromophore VIb. Wherein, the molar ratio of compound 18 and thiobarbital is 1:1.3. IR: 1655 cm ^-1 (C=O). UV-Vis (chloroform, λmax): 586 nm

Synthesis of chromophore VIc

Add compound 18 into a 100ml round bottom flask, and then add ethanol to dissolve it. Weigh 3-phenylisoxazolone into the reaction solution, raise the temperature to 80° C., and stir for 4 hours. The ethanol was spinned off, and column chromatography was performed with _CHCl3 as eluent to obtain the blue-black microcrystalline chromophore VIc. Wherein, the molar ratio of compound 18 and 3-phenylisoxazolone is 1:1. IR: 1730cm ^-1 (C=O). UV-Vis (chloroform, λmax): 562 nm.

Synthesis of Chromophore VId

Add compound 18 into a 100ml round bottom flask, and then add ethanol to dissolve it. Weigh 2-dicyanomethylene-3-cyano-4,5,5-trimethyl-2,5-dihydrofuran into the reaction solution, raise the temperature to 80°C, and stir for 4 hours. Ethanol was removed by spin, and column chromatography was performed with a mixed solvent of CHCl ₃ : ethyl acetate = 20:3 (volume ratio) as eluent to obtain blue-black microcrystalline chromophore VId. Wherein, the molar ratio of compound 18 to 2-dicyanomethylene-3-cyano-4,5,5-trimethyl-2,5-dihydrofuran is 1:1.2. IR: 2222 cm ^-1 (C≡N). UV-Vis (chloroform, λmax): 636 nm.

Claims (2)

1. the second-order nonlinear optical chromophore that contains indolyl radical, its general structure is:

R is C in the formula ₁-C ₉Alkyl or C ₇-C ₁₁Aromatic group; X is oxygen or sulphur atom, and A is selected from following electron-withdrawing group: propane dinitrile, thiobarbituricacid, 3-phenyl-isoxazolidinones, 2-dicyano methylene radical-3-cyano group-4,5,5-trimethylammonium-2,5-dihydrofuran.

2. the described method for making that contains the second-order nonlinear optical chromophore of indolyl radical of claim 1 is characterized in that: with indoles and C ₁-C ₉Halogenated alkane or C ₇-C ₁₁Halogenated aryl hydrocarbon be feedstock production substituted indole A, wherein indoles and C ₁-C ₉Halogenated alkane or C ₇-C ₁₁The molar ratio of halogenated aryl hydrocarbon be 1: 1.0～2.0, substituted indole A is connected with C on the N atom ₁-C ₉Alkyl or C ₇-C ₁₁The indoles of aromatic group; Substituted indole A and N, dinethylformamide and phosphorus oxychloride reaction, preparation indolal B, wherein substituted indole A, N, the mol ratio of dinethylformamide, phosphorus oxychloride is 1: 1.1～1.9: 1.1～1.9; Indolal B and bromo furan methyl triphenyl phosphine or bromo thiophene methyl triphenyl phosphine reaction then, preparation vinyl indoles furans C or vinyl indoles thiophene D, wherein the mol ratio of indolal B and bromo furan methyl triphenyl phosphine or bromo thiophene methyl triphenyl phosphine is 1: 1.0～2.0; Vinyl indoles furans C and N, dinethylformamide and phosphorus oxychloride reaction, preparation vinyl indoles Furan Aldehydes E, therein ethylene base indoles furans C, N, the mol ratio of dinethylformamide, phosphorus oxychloride is 1: 1.1～1.9: 2.0～3.7; Perhaps vinyl indoles thiophene D and n-Butyl Lithium and N, dinethylformamide prepared in reaction vinyl indoles thiophene aldehyde F, therein ethylene base indoles thiophene D and n-Butyl Lithium and N, the mol ratio of dinethylformamide is 1: 1.1～1.5: 1.0～1.4; Be raw material with vinyl indoles Furan Aldehydes E or vinyl indoles thiophene aldehyde F at last, with propane dinitrile, thiobarbituricacid, 3-phenyl-isoxazolidinones or 2-dicyano methylene radical-3-cyano group-4,5,5-trimethylammonium-2, the reaction of 5-dihydrofuran, make the described second-order nonlinear optical chromophore that contains indolyl radical of claim 1, the mol ratio between therein ethylene base indoles Furan Aldehydes E or vinyl indoles thiophene aldehyde F and the various drawing electron group is 1: 1～1.3.