CN114957287B - Highly stable organic near infrared absorbent and preparation method and application thereof - Google Patents

Abstract

The invention discloses a highly stable organic near-infrared absorber and its preparation method and application. The organic near-infrared absorber is N,N'-(((6-methyl-[1,2,5]thiadiazolo[3,4-g]quinoxaline-4,9-diyl) Bis(thiophene‑5,2‑diyl)bis(4,1‑phenylene))bis(N‑phenylnaphthalene‑1‑amine), composed of 4,7‑bis(5‑(4‑(naphthalene) ‑1‑yl(phenyl)amino)phenyl)thiophen‑2‑yl)benzo[c][1,2,5]thiadiazole‑5,6‑diamine and methylglyoxal in dichloro obtained by stirring the reaction in methane at room temperature. The absorbent of the present invention has high stability (including storage stability, chemical stability and light stability), has a wide absorption band of 600-900nm in the heat-insulating coating, and has a simple preparation method and can be used as a heat-insulating coating. Or additive near-infrared absorbers in thermal insulation protective materials.

Description

A highly stable organic near-infrared absorber and its preparation method and application

Technical field

The invention belongs to the technical field of organic near-infrared absorber preparation, and specifically relates to a highly stable organic near-infrared absorber and its preparation method and application.

Background technique

Thermal radiation of sunlight brings many hazards to the environment and daily life. At present, there are generally three types of thermal insulation protection materials for sunlight. The first is barrier coating material: sunlight mainly transfers heat to objects such as buildings or car windows through thermal conduction, and barrier coating achieves resistance to heat transfer by adding insulating fillers with low thermal conductivity, thereby Achieve passive cooling. The second type is radiation coating material: its main principle is to reduce the temperature of objects exposed to sunlight by absorbing solar heat and dissipating it in the form of thermal radiation. The third type is reflective coating material: specifically, it reflects the sun's heat back to the external space. The heat insulation effect is related to the reflectivity of the coating. Therefore, the selection of appropriate additives is of great significance to the performance of thermal insulation coatings and the thermal insulation protection of buildings, car windows, and agricultural greenhouse films.

The energy proportion of sunlight in the ultraviolet region (200-400nm) is 5%, the energy proportion in the visible light region (400-720nm) is 45%, and the energy proportion in the near-infrared region (720-2500nm) is 50% . It can be seen that half of the solar heat comes from the near-infrared region. Therefore, screening materials with near-infrared region absorption as additives plays a key role in preparing high-quality thermal insulation coatings. At present, materials with near-infrared absorption mainly include inorganic near-infrared absorption materials and organic near-infrared absorption materials. Among them, inorganic near-infrared absorbing materials are mainly metal oxides, metal sulfides, and nanometals. However, these materials are mostly composed of multiple components. Their properties are difficult to control and they contain toxic metals, which are potentially harmful to the environment. The properties of organic near-infrared absorbing materials are easy to control, and near-infrared absorbing materials with stable properties can be designed. However, the problem with most organic near-infrared absorbing dyes is that due to the large conjugation and planarity of the materials, the materials are easy to stack and aggregate. , the absorbed near-infrared light energy is difficult to efficiently dissipate through thermal radiation, so the material is easily exposed to oxidants or reducing agents in the environment or strong light (such as oxygen in the air, hydrogen sulfide, sunlight, light, etc.) It is damaged and loses its efficacy, resulting in poor storage stability, poor chemical stability, and poor light stability. Therefore, it is particularly important to prepare organic near-infrared absorbers with good stability.

At present, certain progress has been made in the preparation and application of near-infrared absorbing materials. For example, the Chinese patent "A Transparent Heat-insulating Coating of Near-Infrared Absorbing Pigment and Preparation Method" prepares a near-infrared absorbing pigment that can be used in a transparent heat-insulating coating by doping copper sulfide pigment with metal ions as a near-infrared absorbing pigment. The absorbent is then blended with a transparent resin dispersion and then coated on the substrate to form a coating. Since heavy metal ions are introduced during the preparation of materials, they may cause harm to the environment. The Chinese patent "A type of dye with strong absorption and photothermal effect in the near-infrared region and its preparation method and application" prepares a type of organic material with strong absorption in the near-infrared region. Its main structure is cyanine containing oxonium ions. Dyes, although the absorption range of these dyes can be adjusted and they have strong absorption in the near-infrared region, their chemical stability is relatively poor (storage stability, chemical stability, and light stability are poor), so it is difficult to promote and apply it. . The Chinese patent "A Near-Infrared Absorbing Heat Insulating Film Material and its Preparation Method" prepares a near infrared absorbing heat insulating film material, which includes diisocyanate, polyether and heptamethacyanine dyes containing two active hydroxyl functional groups. etc., the thermal insulation film material can absorb near-infrared light in the range of 700-880nm; however, the light absorber heptamethanine dye also has poor storage stability, chemical stability, and light stability. Shortcomings.

Therefore, it is of great significance to develop and prepare highly stable organic near-infrared absorbers as important additives for thermal insulation coatings or thermal insulation protection materials.

Contents of the invention

In order to solve the above shortcomings and shortcomings of the prior art, the present invention introduces methylglyoxal into the donor-acceptor-donor type molecular structure in which benzothiadiazole is the acceptor core, forming benzothiadiazole. The azoquinoxaline acceptor core not only ensures the electron-withdrawing ability of the acceptor core, but also introduces a methyl group on the core that can rotate around a single bond, destroying the large planarity of the structure, avoiding molecular stacking, and improving the stability of the material. ; In addition, N,N-diphenyl-1-naphthylamine groups are introduced on both sides of the molecular structure. On the one hand, it serves as an electron-donating group. On the other hand, the twisted conformation of diphenyl-naphthylamine is conducive to improving steric hindrance. Thereby preventing the attack of oxidants or reducing agents and the occurrence of redox reactions under light, thereby improving chemical stability, storage stability and photostability. The absorption of molecules can reach the near-infrared region, and the near-infrared absorber is highly stable and can not deteriorate under continuous irradiation of near-infrared light, which can meet the requirements of near-infrared absorption in thermal insulation coatings or thermal insulation protective materials. agent needs.

The object of the present invention is to provide a highly stable organic near-infrared absorber, a preparation method of the absorber and the application of the absorber as an additive near-infrared absorber in a thermal insulation coating or thermal insulation protective material.

The object of the present invention is achieved through the following technical solutions:

The invention provides a highly stable organic near-infrared absorber, which is characterized in that the organic near-infrared absorber is N,N'-(((6-methyl-[1,2,5]thiadiazolo) [3,4-g]quinoxaline-4,9-diyl)bis(thiophene-5,2-diyl))bis(4,1-phenylene))bis(N-phenylnaphthalene-1) -amine), has the following structural formula:

The invention provides a method for preparing a highly stable organic near-infrared absorber, which includes the following steps:

4,7-Bis(5-(4-(naphth-1-yl(phenyl)amino)phenyl)thiophen-2-yl)benzo[c][1,2,5]thiadiazole-5 , 6-diamine and methylglyoxal are dissolved in methylene chloride, stirred and reacted, and purified after the reaction is completed to obtain the organic near-infrared absorber.

Preferably, the 4,7-bis(5-(4-(naphth-1-yl(phenyl)amino)phenyl)thiophen-2-yl)benzo[c][1,2,5]thiophene The molar ratio of diazole-5,6-diamine to methylglyoxal is 1:2-4.

Preferably, the 4,7-bis(5-(4-(naphth-1-yl(phenyl)amino)phenyl)thiophen-2-yl)benzo[c][1,2,5]thiophene The molar volume ratio of diazole-5,6-diamine and dichloromethane is 1mmol:25-30mL.

Preferably, the temperature of the stirring reaction is room temperature.

Preferably, the stirring reaction time is 1-2 hours.

Preferably, the purification is silica gel chromatography.

Further preferably, the eluent of the silica gel chromatography is n-hexane/dichloromethane.

The present invention also provides the application of the above-mentioned highly stable organic near-infrared absorber as an additive near-infrared absorber in a heat-insulating coating or heat-insulating protective material.

The product synthesized by the above preparation method is N,N'-(((6-methyl-[1,2,5]thiadiazolo[3,4-g]quinoxaline-4,9-diyl)bis (thiophene-5,2-diyl))bis(4,1-phenylene))bis(N-phenylnaphthyl-1-amine) (TQBN), the molecular formula is C ₆₁ H ₄₀ N ₆ S ₃ , relative The molecular mass is 952.2477. TQBN is a green solid powder, insoluble in water, and easily soluble in organic solvents such as dichloromethane, tetrahydrofuran, N,N-dimethylformamide and dimethyl sulfoxide. The synthesis route is as follows:

Compared with the existing technology, the present invention has the following beneficial effects:

(1) The organic near-infrared absorber of the present invention is simple to prepare, has good stability, is non-toxic, and is environmentally friendly. In its molecular structure, there is a freely rotating methyl group on the central acceptor core, and diphenyl-naphthylamine groups with a twisted structure on both sides. The phenyl and naphthyl groups can freely rotate. The large planarity caused by conjugation and the molecular stacking induced thereby can be effectively avoided. In addition, the large steric hindrance in the middle and both sides of the molecule can prevent the attack of oxidants or reducing agents in the environment and prevent the redox reaction under light conditions. Therefore, the material has a high degree of stability, including storage stability. , chemical stability and photostability. In addition, the free rotation of the methyl group in the middle of the molecule and the free rotation of the phenyl and naphthyl groups on both sides are conducive to the efficient dissipation of the absorbed near-infrared light energy in the form of thermal radiation, thus protecting the objects inside the thermal insulation layer. the goal of.

(2) The absorption band of the organic near-infrared absorber (TQBN) of the present invention extends to the near-infrared absorption region, and the absorption wavelength in the transparent heat-insulating coating covers 600-900nm, so it is suitable for use in heat-insulating coatings or heat-insulating protective materials. Used as a near-infrared absorber.

Description of the drawings

Figure 1 is a synthesis route diagram of the organic near-infrared absorber of the present invention.

Figure 2 shows N,N'-(((6-methyl-[1,2,5]thiadiazolo[3,4-g]quinoxaline-4,9-diyl)bis in Example 1 H NMR spectrum of (thiophene-5,2-diyl)bis(4,1-phenylene))bis(N-phenylnaphthalene-1-amine) (TQBN);

Figure 3 shows N,N'-(((6-methyl-[1,2,5]thiadiazolo[3,4-g]quinoxaline-4,9-diyl)bis in Example 1 Matrix-assisted laser desorption ionization time-of-flight mass spectrum of (thiophene-5,2-diyl)bis(4,1-phenylene))bis(N-phenylnaphthalene-1-amine) (TQBN);

Figure 4 shows N,N'-(((6-methyl-[1,2,5]thiadiazolo[3,4-g]quinoxaline-4,9-diyl)bis in Example 4 Absorption spectra of (thiophene-5,2-diyl)bis(4,1-phenylene))bis(N-phenylnaphthyl-1-amine) (TQBN) in clear coating.

Figure 5 shows N,N'-(((6-methyl-[1,2,5]thiadiazolo[3,4-g]quinoxaline-4,9-diyl)bis in Example 4 Absorbance change chart of (thiophene-5,2-diyl)bis(4,1-phenylene))bis(N-phenylnaphthyl-1-amine) (TQBN) under 808nm laser irradiation.

Detailed ways

The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings and examples, but the implementation and protection of the present invention are not limited thereto. It should be pointed out that any process that is not specifically described in detail below can be implemented or understood by those skilled in the art with reference to the existing technology. If the manufacturer of the reagents or instruments used is not indicated, they are regarded as conventional products that can be purchased commercially.

4,7-bis(5-(4-(naphth-1-yl(phenyl)amino)phenyl)thiophen-2-yl)benzo[c][1,2,5]thiophen used in the examples Diazole-5,6-diamine is referred to the literature Chen J, Chen L, Fang Y, et al. Refashioningbenzothiadiazole dye as an activatable nanoprobe for biomarker detection withNIR-II fluorescence/optoacoustic imaging[J].Cell Reports Physical Science, 2022 , 3(2):100570. Prepared by the reported method. The details are as follows: N,N'-(((5,6-dinitrobenzo[c][1,2,5]thiadiazole-4,7-diyl)bis(thiophene-5,2-di Base))bis(4,1-phenylene))bis(N-phenylnaphthyl-1amine) and iron powder were added to the acetic acid solvent, then heated to 80°C and stirred overnight. After the reaction was completed, the acetic acid was removed by rotary evaporation Solvent, and then separated by silica gel chromatography column to obtain 4,7-bis(5-(4-(naphth-1-yl(phenyl)amino)phenyl)thiophen-2-yl)benzo[c][1, 2,5]thiadiazole-5,6-diamine.

Example 1

The organic near-infrared absorber N,N'-(((6-methyl-[1,2,5]thiadiazolo[3,4-g]quinoxaline-4,9-diyl The synthetic route of bis(thiophene-5,2-diyl))bis(4,1-phenylene))bis(N-phenylnaphthalene-1-amine) (TQBN) is shown in Figure 1. The specific steps as follows:

4,7-Bis(5-(4-(naphth-1-yl(phenyl)amino)phenyl)thiophen-2-yl)benzo[c][1,2,5]thiadiazole-5 , 55 mg of 6-diamine (0.06 mmol) and 7.21 μL of methylglyoxal (0.12 mmol) were dissolved in 1.5 mL of methylene chloride, and the reaction was stirred at room temperature for 1 hour, and then purified by silica gel chromatography (eluent used is n-hexane/dichloromethane, V/V=1:1), and the absorbent N,N'-(((6-methyl-[1,2,5]thiadiazolo[3,4 -g]quinoxaline-4,9-diyl)bis(thiophene-5,2-diyl))bis(4,1-phenylene))bis(N-phenylnaphthalene-1-amine)( TQBN) 54 mg, the yield was 94%.

The prepared compound was characterized by hydrogen nuclear magnetic resonance spectrum: ¹ H NMR (600MHz, Chloroform-d) δ8.85-8.76 (d, J=53.0Hz, 2H), 8.49 (s, 1H), 7.96-7.80 (m,8H),7.56-7.38(m,14H),7.13-7.02(m,12H),2.67(s,3H). The hydrogen nuclear magnetic resonance spectrum is shown in Figure 2, confirming that the compound is N,N'-(((6-methyl-[1,2,5]thiadiazolo[3,4-g]quinoxaline- 4,9-diyl)bis(thiophene-5,2-diyl))bis(4,1-phenylene))bis(N-phenylnaphthalene-1-amine).

In addition, the prepared compounds were further verified through matrix-assisted laser desorption ionization time-of-flight mass spectrometry testing: MALDITOF-MS (ESI, m/z): The theoretically calculated molecular mass-to-charge ratio is [M+H] ⁺ C ₆₁ H ₄₁ N ₆ S ₃ : 953.2555, the actual measured mass-to-charge ratio of the molecule is: 953.2557; the matrix-assisted laser desorption ionization time-of-flight mass spectrum is shown in Figure 3. Describe the prepared compound N,N'-(((6-methyl-[1,2,5]thiadiazolo[3,4-g]quinoxaline-4,9-diyl)bis(thiophene) The structure of -5,2-diyl))bis(4,1-phenylene))bis(N-phenylnaphthalene-1-amine) is as expected.

Example 2

The organic near-infrared absorber N,N'-(((6-methyl-[1,2,5]thiadiazolo[3,4-g]quinoxaline-4,9-diyl The synthetic route of bis(thiophene-5,2-diyl))bis(4,1-phenylene))bis(N-phenylnaphthalene-1-amine) (TQBN) is shown in Figure 1. The specific steps as follows:

4,7-Bis(5-(4-(naphth-1-yl(phenyl)amino)phenyl)thiophen-2-yl)benzo[c][1,2,5]thiadiazole-5 , 131 mg of 6-diamine (0.14 mmol) and 25.81 μL of methylglyoxal (0.43 mmol) were dissolved in 4 mL of methylene chloride, and the reaction was stirred at room temperature for 1.5 hours, and then purified by silica gel chromatography (the eluent used was n-hexane/dichloromethane, V/V=1:1), the absorbent N,N'-(((6-methyl-[1,2,5]thiadiazolo[3,4- g]quinoxaline-4,9-diyl)bis(thiophene-5,2-diyl)bis(4,1-phenylene))bis(N-phenylnaphthalene-1-amine)(TQBN )126mg, the yield is 93%.

The characterization results of compound TQBN obtained in this example are the same as those in Example 1.

Example 3

The organic near-infrared absorber N,N'-(((6-methyl-[1,2,5]thiadiazolo[3,4-g]quinoxaline-4,9-diyl The synthetic route of bis(thiophene-5,2-diyl))bis(4,1-phenylene))bis(N-phenylnaphthalene-1-amine) (TQBN) is shown in Figure 1. The specific steps as follows:

4,7-Bis(5-(4-(naphth-1-yl(phenyl)amino)phenyl)thiophen-2-yl)benzo[c][1,2,5]thiadiazole-5 , 293.2 mg of 6-diamine (0.40 mmol) and 96.03 μL of methylglyoxal (1.60 mmol) were dissolved in 12 mL of methylene chloride, and the reaction was stirred at room temperature for 2 hours, and then purified by silica gel chromatography (eluent used is n-hexane/dichloromethane, V/V=1:1), and the absorbent N,N'-(((6-methyl-[1,2,5]thiadiazolo[3,4 -g]quinoxaline-4,9-diyl)bis(thiophene-5,2-diyl))bis(4,1-phenylene))bis(N-phenylnaphthalene-1-amine)( TQBN) 335 mg, yield 88%.

The characterization results of compound TQBN obtained in this example are the same as those in Example 1.

Example 4

Absorption spectrum test of organic near-infrared absorber TQBN in transparent coating.

4.75 mg of the solid compound N,N'-(((6-methyl-[1,2,5]thiadiazolo[3,4-g]quinoxaline-4,9-di Bis(thiophene-5,2-diyl)bis(4,1-phenylene))bis(N-phenylnaphthalene-1-amine)(TQBN) was doped into the clear coating for testing. The test temperature is 25°C, and the results are shown in Figure 4. It can be seen from Figure 4 that it has a strong absorption band in the range of 600-900nm in the transparent coating (the maximum absorption wavelength is 727nm), indicating that the absorber prepared by the present invention has a wide absorption band of near-infrared light and is suitable for It is suitable for use as a near-infrared absorber in thermal insulation coatings or thermal insulation protective materials.

Stability test of organic near-infrared absorber TQBN.

Compound N,N'-(((6-methyl-[1,2,5]thiadiazolo[3,4-g]quinoxaline-4,9-diyl)bis prepared in Example 1 (thiophene-5,2-diyl)bis(4,1-phenylene))bis(N-phenylnaphthyl-1-amine)(TQBN) is dissolved in N,N-dimethylformamide. into a 1mM compound stock solution. The stock solution was diluted with N,N-dimethylformamide to a final concentration of 20 μM, the total test volume was 3 mL, and the test temperature was 25°C. The solution was continuously irradiated with 808nm as the excitation wavelength and a power of 100mW/ ^cm2 , and then the absorption spectrum was measured at 0, 20, 40, 60, 80, 100, and 120 minutes and the absorbance at 727nm was plotted. The measured absorbance changes with laser irradiation time as shown in Figure 5. It can be seen from Figure 5 that under the continuous radiation of the 808nm laser, the absorbance of the absorber molecule at 727nm is almost unchanged, indicating that the absorbent prepared by the present invention The organic near-infrared absorber has good photostability.

In addition, the prepared near-infrared absorber showed no deterioration after being stored in a normal environment for one year, indicating that it has good storage stability, ambient light stability and environmental chemical stability. Therefore, the organic near-infrared absorber of the present invention is suitable as an additive near-infrared absorber in heat-insulating coatings or heat-insulating protective materials.

The above examples are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications may be made without departing from the spirit and principles of the present invention. , should be equivalent replacement methods, and are included in the protection scope of the present invention.

Claims (5)

1. A highly stable organic near-infrared absorber used as a thermal insulation coating or thermal insulation protective material, characterized in that the organic near-infrared absorber is N,N'-(((6-methyl- [1,2,5]thiadiazolo[3,4-g]quinoxaline-4,9-diyl)bis(thiophene-5,2-diyl))bis(4,1-phenylene) )) bis(N-phenylnaphthalene-1-amine), has the following structural formula: 2. The preparation method of a highly stable organic near-infrared absorber according to claim 1, characterized in that the synthesis route is as follows: 3. The preparation method of a highly stable organic near-infrared absorber according to claim 2, characterized in that it includes the following steps: 4,7-Bis(5-(4-(naphth-1-yl(phenyl)amino)phenyl)thiophen-2-yl)benzo[c][1,2,5]thiadiazole-5 , 6-diamine and methylglyoxal are dissolved in dichloromethane, stirred and reacted, and purified after the reaction is completed to obtain the organic near-infrared absorber; the 4,7-bis(5-(4-(naphthalene The molar ratio of -1-yl(phenyl)amino)phenyl)thiophen-2-yl)benzo[c][1,2,5]thiadiazole-5,6-diamine to methylglyoxal is 1:2-4; The 4,7-bis(5-(4-(naphth-1-yl(phenyl)amino)phenyl)thiophen-2-yl)benzo[c][1,2,5]thiadiazole- The molar volume ratio of 5,6-diamine and dichloromethane is 1mmol:25-30mL; The temperature of the stirring reaction is room temperature; The stirring reaction time is 1-2 hours. 4. The preparation method of a highly stable organic near-infrared absorber according to claim 3, characterized in that the purification is silica gel chromatography. 5. The method for preparing a highly stable organic near-infrared absorber according to claim 4, characterized in that the eluent of the silica gel chromatography is n-hexane/methylene chloride.