阅读说明：本技术 一种近红外强吸收染料及其制备方法与应用 (Near-infrared strong absorption dye and preparation method and application thereof ) 是由 吴水珠 陈龙琦 陈俊杰 曾钫 于 2021-06-18 设计创作，主要内容包括：本发明公开了一种近红外强吸收染料及其制备方法与应用；本发明的染料为2-(3-氰基-4-(2-(3-(-2-(4-氰基-5-(二氰甲基)-2,2-二甲基呋喃-3(2H)-亚基)亚乙基)-2-(哌嗪-1-基)环己-1-烯-1-基)乙烯基)-5,5-二甲基呋喃-2(5H)-亚基)丙二腈；本发明的染料制备方法简单；其在700nm-900nm内可以有效吸收近红外光,吸收峰宽而强,最大吸收峰在770nm；本发明的染料可以用于激光防护等领域。(The invention discloses a near-infrared strong absorption dye and a preparation method and application thereof; the dye of the invention is 2- (3-cyano-4- (2- (3- (-2- (4-cyano-5- (dicyanomethyl) -2, 2-dimethylfuran-3 (2H) -ylidene) ethylene) -2- (piperazin-1-yl) cyclohex-1-en-1-yl) vinyl) -5, 5-dimethylfuran-2 (5H) -ylidene) malononitrile; the dye of the invention has simple preparation method; the near-infrared light can be effectively absorbed within 700nm-900nm, the absorption peak is wide and strong, and the maximum absorption peak is 770 nm; the dye can be used in the fields of laser protection and the like.)

1. A near infrared strong absorption dye, which is 2- (3-cyano-4- (2- (3- (-2- (4-cyano-5- (dicyanomethyl) -2, 2-dimethylfuran-3 (2H) -ylidene) ethylene) -2- (piperazin-1-yl) cyclohex-1-en-1-yl) ethenyl) -5, 5-dimethylfuran-2 (5H) -ylidene) malononitrile, having the following structural formula:

2. the method for preparing the near-infrared strong absorption dye according to claim 1, characterized by comprising the following steps:

dissolving 2- (4- (2- (2-chloro-3- (2- (4-cyano-5- (dicyanomethylene) -2, 2-dimethyl-2, 5-dihydrofuran-3-yl) vinyl) cyclohex-2-en-1-ylidene) ethylene) -3-cyano-5, 5-dimethyl-4, 5-dihydrofuran-2-yl) malononitrile with piperazine and N, N-dimethylformamide, stirring at room temperature under a protective atmosphere, and purifying to obtain the near infrared strong absorption dye.

3. The process according to claim 2, wherein the molar ratio of 2- (4- (2- (2-chloro-3- (2- (4-cyano-5- (dicyanomethylene) -2, 2-dimethyl-2, 5-dihydrofuran-3-yl) vinyl) cyclohex-2-en-1-ylidene) ethylene) -3-cyano-5, 5-dimethyl-4, 5-dihydrofuran-2-yl) malononitrile to piperazine is 1: 4-4.1.

4. The method according to claim 2, wherein the molar volume ratio of 2- (4- (2- (2-chloro-3- (2- (4-cyano-5- (dicyanomethylene) -2, 2-dimethyl-2, 5-dihydrofuran-3-yl) vinyl) cyclohex-2-en-1-ylidene) ethylene) -3-cyano-5, 5-dimethyl-4, 5-dihydrofuran-2-yl) malononitrile to N, N-dimethylformamide is 1mmol:10 to 15 mL.

5. The method of claim 2, wherein the stirring is carried out at room temperature for 12 to 14 hours.

6. The method according to claim 2, wherein the protective atmosphere is a nitrogen atmosphere.

7. The preparation method according to claim 6, wherein the protective atmosphere is formed by vacuumizing and filling nitrogen into the system and repeating the vacuumizing and filling nitrogen for at least 3 times.

8. The method of claim 2, wherein the purification is silica gel chromatography.

9. The method according to claim 8, wherein the eluent for silica gel chromatography is dichloromethane/methanol.

10. The use of the near infrared strong absorption dye of claim 1 as laser protection material and in the preparation of laser protection material.

Technical Field

The invention belongs to the technical field of synthesis of near-infrared absorption dyes, and particularly relates to a near-infrared strong absorption dye and a preparation method and application thereof.

Background

Near infrared absorbing dyes are a class of dyes whose main absorption band is in the near infrared region. With the rapid development of the photoelectric functional material industry, people have attracted much attention in many fields including optical recording systems, laser filtering, laser printing, infrared photography, and the like due to the remarkable optical characteristics thereof. Laser is another important invention after human beings continue nuclear energy, computers and semiconductors, and at present, along with the continuous expansion of the application of laser in military and civil fields, the hazard of laser and the appearance of laser weapons also arouse attention of people to laser protection. The wavelength of the shielding is also shifted from the conventional visible region to the near infrared region. The material is required to have strong absorption in a near infrared (700 nm) region, no absorption or weak absorption in a visible light region, good light, heat and chemical stability, good compatibility with a polymer matrix material and good compatibility with the matrix material, and can be blended or grafted with a polymer substrate to form a laser protection film or sheet. The organic near-infrared absorption material has the advantages of high synthesis feasibility and low economic cost, and is a main way for realizing near-infrared laser protection.

It is reported that various types of near infrared absorbing dyes have been developed at home and abroad, and mainly classified into cyanine dyes, phthalocyanine dyes, and metal complex dyes. The cyanine dyes have been studied most actively in recent years, and the maximum absorption wavelength of the dye can be changed by controlling the length of the conjugated main chain by adjusting the number of vinyl groups in the cyanine dyes. In addition, such dyes also have a large molar extinction coefficient, but their practical application is greatly limited due to their poor photostability. Chinese patent 201811293743.7 discloses a piperidine-modified heptamethine indocyanine dye, which improves the light stability of indocyanine dye, but the maximum absorption peak is blue-shifted from 785nm to about 700nm, resulting in a significantly narrowed near-infrared absorption band; the near-infrared absorption dye based on alkynyl triphenylamine and perylene diimide is prepared in Chinese patent 201810030698.X, can absorb near-infrared light in the range of 650 plus 750nm, has a narrow infrared absorption band, is complex to synthesize, and is not beneficial to practical application. Chinese patent 201010203753.4 discloses a POSS hybrid squarylium cyanine dye which can effectively absorb near infrared light within the absorption wavelength range of 650 plus 800 nm; meanwhile, the stability of the dye is improved by adopting an organic-inorganic hybridization mode; however, because the dye has no redundant active sites, the obtained POSS hybrid dye is difficult to further modify, and the application range of the POSS hybrid dye is limited.

Disclosure of Invention

In order to solve the defects and shortcomings of the prior art, the piperazine group is introduced into the heptamethine tricyanofurancyanine dye, so that the heptamethine tricyanofurancyanine dye has wide and strong near-infrared absorption characteristics, the light stability of the dye is improved, and a secondary amine group on the piperazine can be used as a reserved active group to provide an active site for further grafting the piperazine group onto a polymer base material, so as to meet the requirements for laser protection application.

The invention aims to prepare a dye with strong absorption in the near-infrared wavelength range of 700-900nm, wherein a material skeleton is a conjugated chain consisting of methine (CH) n, and the two ends of the conjugated chain are connected with tricyanofuran and the conjugated chain to form a large conjugated system; overcomes the defect of poor light stability of the traditional cyanine dye, and can reserve active sites for reaction with a polymer substrate.

The purpose of the invention is realized by the following technical scheme:

a near infrared strong absorbing dye which is 2- (3-cyano-4- (2- (3- (-2- (4-cyano-5- (dicyanomethyl) -2, 2-dimethylfuran-3 (2H) -ylidene) ethylene) -2- (piperazin-1-yl) cyclohex-1-en-1-yl) vinyl) -5, 5-dimethylfuran-2 (5H) -ylidene) malononitrile having the formula:

the preparation method of the near-infrared strong absorption dye comprises the following steps:

dissolving 2- (4- (2- (2-chloro-3- (2- (4-cyano-5- (dicyanomethylene) -2, 2-dimethyl-2, 5-dihydrofuran-3-yl) vinyl) cyclohex-2-en-1-ylidene) ethylene) -3-cyano-5, 5-dimethyl-4, 5-dihydrofuran-2-yl) malononitrile with piperazine and N, N-dimethylformamide, stirring at room temperature under a protective atmosphere, and purifying to obtain the near infrared strong absorption dye.

Preferably, the molar ratio of 2- (4- (2- (2-chloro-3- (2- (4-cyano-5- (dicyanomethylene) -2, 2-dimethyl-2, 5-dihydrofuran-3-yl) vinyl) cyclohex-2-en-1-ylidene) ethylene) -3-cyano-5, 5-dimethyl-4, 5-dihydrofuran-2-yl) malononitrile to piperazine is 1: 4-4.1.

Preferably, the molar volume ratio of the 2- (4- (2- (2-chloro-3- (2- (4-cyano-5- (dicyanomethylene) -2, 2-dimethyl-2, 5-dihydrofuran-3-yl) vinyl) cyclohex-2-en-1-ylidene) ethylene) -3-cyano-5, 5-dimethyl-4, 5-dihydrofuran-2-yl) malononitrile to the N, N-dimethylformamide is 1mmol:10-15 mL.

Preferably, the stirring time at room temperature is 12 to 14 hours.

Preferably, the protective atmosphere is a nitrogen atmosphere.

Further preferably, the protective atmosphere is formed by vacuumizing and filling nitrogen into the system and repeating the vacuumizing and filling nitrogen for at least 3 times.

Preferably, the purification is silica gel chromatography.

Further preferably, the eluent for silica gel chromatography is dichloromethane/methanol.

The near-infrared strong absorption dye is applied to laser protection materials and preparation of the laser protection materials.

Compared with the prior art, the invention has the following beneficial effects:

the product obtained by the invention is 2- (3-cyano-4- (2- (3- (-2- (4-cyano-5- (dicyanomethyl) -2, 2-dimethylfuran-3 (2H) -ylidene) ethylidene) -2- (piperazin-1-yl) cyclohex-1-en-1-yl) ethenyl) -5, 5-dimethylfuran-2 (5H) -ylidene) malononitrile (Cy-NN), and the molecular formula is C₃₄H₃₂N₈O₂The relative molecular mass was 584.26. Cy-NN is golden yellow solid powder, is insoluble in water, and is easily soluble in organic solvents such as dichloromethane, N-dimethylformamide, dimethyl sulfoxide and the like. The compound has good light stability, good chemical stability, no toxicity and good near infrared light absorption performance. Piperazine is introduced into the heptamethine tricyanofurancyanine dye molecule, so that the light stability of the dye is greatly improved, the near-infrared absorption characteristic of the dye is not obviously influenced, the absorption wavelength range is 600-900nm, the absorption peak value is 770nm, and in addition, the dye is reserved and polymerizedActive sites for substrate reaction. Therefore, the heptamethine tricyanofurancyanine dye with the piperazine structure introduced can be applied to the field of laser protection.

Drawings

FIG. 1 is a diagram of the synthetic route for the near infrared strongly absorbing dyes of the present invention.

FIG. 2 is a nuclear magnetic resonance hydrogen spectrum of 2- (3-cyano-4- (2- (3- (-2- (4-cyano-5- (dicyanomethyl) -2, 2-dimethylfuran-3 (2H) -ylidene) ethylene) -2- (piperazin-1-yl) cyclohex-1-en-1-yl) vinyl) -5, 5-dimethylfuran-2 (5H) -ylidene) malononitrile (Cy-NN) in example 1;

FIG. 3 is a high resolution mass spectrum of 2- (3-cyano-4- (2- (3- (-2- (4-cyano-5- (dicyanomethyl) -2, 2-dimethylfuran-3 (2H) -ylidene) ethylene) -2- (piperazin-1-yl) cyclohex-1-en-1-yl) vinyl) -5, 5-dimethylfuran-2 (5H) -ylidene) malononitrile (Cy-NN) of example 1;

FIG. 4 is an absorption spectrum of 2- (3-cyano-4- (2- (3- (-2- (4-cyano-5- (dicyanomethyl) -2, 2-dimethylfuran-3 (2H) -ylidene) ethylene) -2- (piperazin-1-yl) cyclohex-1-en-1-yl) vinyl) -5, 5-dimethylfuran-2 (5H) -ylidene) malononitrile (Cy-NN) in example 1;

FIG. 5 shows the reaction product of 2- (3-cyano-4- (2- (3- (-2- (4-cyano-5- (dicyanomethyl) -2, 2-dimethylfuran-3 (2H) -ylidene) ethylene) -2- (piperazin-1-yl) cyclohex-1-en-1-yl) vinyl) -5, 5-dimethylfuran-2 (5H) -ylidene) malononitrile (Cy-NN) and 2- (4- (2- (2-chloro-3- (2- (4-cyano-5- (dicyanomethylene) -2, 2-dimethyl-2, 5-dihydrofuran-3-yl) vinyl) cyclohex-2-en-1-ylidene) in example 1 Graph comparing light stability of ethyl) -3-cyano-5, 5-dimethyl-4, 5-dihydrofuran-2-yl malononitrile (TCF-Cy) (change in absorbance ratio at 770nm before and after laser irradiation).

Detailed Description

The following description of the embodiments of the present invention is provided in connection with the accompanying drawings and examples, but the invention is not limited thereto. It is noted that the processes described below, if not specifically described in detail, are all realizable or understandable by those skilled in the art with reference to the prior art. The reagents or apparatus used are not indicated to the manufacturer, and are considered to be conventional products available through commercial purchase.

The synthetic route of the near infrared region dye of the invention is shown in figure 1.

Example 1

213.66mg (0.40mmol) of 2- (4- (2-chloro-3- (2- (4-cyano-5- (dicyanomethylene) -2, 2-dimethyl-2, 5-dihydrofuran-3-yl) vinyl) cyclohex-2-en-1-ylidene) ethylene) -3-cyano-5, 5-dimethyl-4, 5-dihydrofuran-2-yl) malononitrile and 137.82mg (1.60mmol) of piperazine were taken in a single-neck flask, and dissolved in 4mL of N, N-dimethylformamide. The system was evacuated under nitrogen and repeated 3 times, and the mixture was stirred at room temperature for 12 hours, after which it was purified by silica gel chromatography (eluent used was dichloromethane/methanol, V/V ═ 25:1) to give 160mg (yield: 68%) of 2- (3-cyano-4- (2- (3- (-2- (4-cyano-5- (dicyanomethyl) -2, 2-dimethylfuran-3 (2H) -ylidene) ethylidene) -2- (piperazin-1-yl) cyclohex-1-en-1-yl) ethenyl) -5, 5-dimethylfuran-2 (5H) -ylidene) malononitrile as the product.

It was characterized by means of nuclear magnetic resonance hydrogen spectroscopy:¹h NMR (600MHz, DMSO-d6) δ 7.88-7.86(d, J ═ 13.3Hz,2H),5.90-5.88(d, J ═ 13.5Hz,2H),3.63-3.61(t, J ═ 5.0Hz,4H),3.35-3.34(t, J ═ 5.2Hz,4H),2.41-2.39(t, J ═ 6.5Hz,4H), 1.68-1.66 (m,2H),1.54(s,12H),1.23(s, 1H). The NMR spectrum is shown in FIG. 2.

Further validation was performed by high resolution mass spectrometry testing: HR-MS (ESI, M/z) with a theoretical calculated molecular mass to charge ratio [ M^-H]^-C₃₄H₃₁N₈O₂583.2570, the actual measured molecular mass-to-charge ratio is 583.2584; the high resolution mass spectrum is shown in figure 3.

Example 2

534.16mg (1.00mmol) of 2- (4- (2- (2-chloro-3- (2- (4-cyano-5- (dicyanomethylene) -2, 2-dimethyl-2, 5-dihydrofuran-3-yl) vinyl) cyclohex-2-en-1-ylidene) ethylene) -3-cyano-5, 5-dimethyl-4, 5-dihydrofuran-2-yl) malononitrile and 348.87mg (4.05mmol) of piperazine were taken in a single-neck flask, and dissolved in 13mL of N, N-dimethylformamide. The system was evacuated under nitrogen and repeated 3 times, and the mixture was stirred at room temperature for 13 hours, after which it was purified by silica gel chromatography (eluent used was dichloromethane/methanol, V/V ═ 25:1) to give the product 2- (3-cyano-4- (2- (3- (-2- (4-cyano-5- (dicyanomethyl) -2, 2-dimethylfuran-3 (2H) -ylidene) ethylidene) -2- (piperazin-1-yl) cyclohex-1-en-1-yl) ethenyl) -5, 5-dimethylfuran-2 (5H) -ylidene) malononitrile 365mg (yield: 62%).

The characterization of the dye Cy-NN obtained in this example was the same as that of example 1.

Example 3

1068.32mg (2.00mmol) of 2- (4- (2-chloro-3- (2- (4-cyano-5- (dicyanomethylene) -2, 2-dimethyl-2, 5-dihydrofuran-3-yl) vinyl) cyclohex-2-en-1-ylidene) ethylene) -3-cyano-5, 5-dimethyl-4, 5-dihydrofuran-2-yl) malononitrile and 706.35mg (8.20mmol) of piperazine were taken in a single-neck flask, and dissolved in 30mL of N, N-dimethylformamide. Vacuumizing the system, filling nitrogen and repeating for 3 times, stirring the mixture at room temperature for 14 hours, extracting a crude product by using water and ethyl acetate, taking an organic phase, drying the organic phase by using anhydrous sodium sulfate, and filtering; the organic solvent was removed by rotary evaporation and the resulting solid was purified by silica gel chromatography (eluent dichloromethane/methanol, V/V ═ 25:1) to give 746mg of 2- (3-cyano-4- (2- (3- (-2- (4-cyano-5- (dicyanomethyl) -2, 2-dimethylfuran-3 (2H) -ylidene) ethylidene) -2- (piperazin-1-yl) cyclohex-1-en-1-yl) ethenyl) -5, 5-dimethylfuran-2 (5H) -ylidene) malononitrile (yield: 64%).

The characterization of the dye Cy-NN obtained in this example was the same as that of example 1.

The 2- (4- (2- (2-chloro-3- (2- (4-cyano-5- (dicyanomethylene) -2, 2-dimethyl-2, 5-dihydrofuran-3-yl) vinyl) cyclohex-2-en-1-ylidene) ethylidene) -3-cyano-5, 5-dimethyl-4, 5-dihydrofuran-2-yl) malononitrile (TCF-Cy) used in examples 1-3 was prepared by the method reported in the references Y.Wu, J.Chen, L.Sun, F.Zeng, S.Wu, A nanoproburic for differentiating and mapping pathological measurements of tumor using 3D multiplex optical mapping with aggregation/aggregation induced diffusion change.

Example 4

Testing near infrared absorption and light stability;

near infrared absorption test

Preparation of Cy-NN absorption Spectroscopy test solution samples

5.84mg of the solid compound 2- (3-cyano-4- (2- (3- (-2- (4-cyano-5- (dicyanomethyl) -2, 2-dimethylfuran-3 (2H) -ylidene) ethylene) -2- (piperazin-1-yl) cyclohex-1-en-1-yl) vinyl) -5, 5-dimethylfuran-2 (5H) -ylidene) malononitrile (Cy-NN) prepared in example 1 was dissolved in 10mL of dimethyl sulfoxide and prepared as a compound mother liquor at a concentration of 1 mM. For the test, the test solution was diluted with dimethyl sulfoxide to a concentration of 10. mu.M, the total amount of the test system was 3mL, and the test temperature was 25 ℃. The absorption spectrum test result is shown in FIG. 4, and it can be seen from FIG. 4 that the maximum absorption peak of the near-infrared absorption organic dye of the present invention is 770nm, which can generate high-efficiency absorption for the near-infrared light of 700-900 nm.

Light stability test of TCF-Cy and Cy-NN

2- (4- (2- (2-chloro-3- (2- (4-cyano-5- (dicyanomethylene) -2, 2-dimethyl-2, 5-dihydrofuran-3-yl) vinyl) cyclohex-2-en-1-ylidene) ethylene) -3-cyano-5, 5-dimethyl-4, 5-dihydrofuran-2-yl) malononitrile (TCF-Cy) was reacted with 2- (3-cyano-4- (2- (3- (-2- (4-cyano-5- (dicyanomethyl) -2, 2-dimethylfuran-3 (2H) -ylidene) ethylene) -2- (piperazin-1-yl) cyclohexanecarbonitrile) prepared in example 1 1-en-1-yl) vinyl) -5, 5-dimethylfuran-2 (5H) -ylidene) malononitrile (Cy-NN) were each prepared as a compound mother liquor at a concentration of 1 mM. For the test, the test solution was diluted with dimethyl sulfoxide to a concentration of 10. mu.M, the total amount of the test system was 3mL, and the test temperature was 25 ℃. Using 80mW/cm²The laser beam of 808nm is continuously irradiated with TCF-Cy and Cy-NN for 60 minutes respectively, absorption spectra are measured at intervals, and the change of the absorbance ratio at 770nm before and after irradiation is calculated. As shown in FIG. 5, A₀Represents the absorbance at 770nm before laser irradiation, A_tRepresents the absorbance at 770nm after laser irradiation, and the graph shows that the absorbance of the TCF-Cy which is not modified by piperazine rapidly decreases after the continuous laser irradiation; after the near-infrared absorption organic dye Cy-NN is continuously irradiated for 1 hour, the absorbance is still kept about 0.8 compared with that before laser irradiation. The result shows that the invention introduces piperazine into heptamethine tricyano furan cyanine dye to leadThe light stability of the obtained dye is greatly improved.

The above examples are preferred embodiments of the present invention, but the present invention is not limited to the above examples, 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.