Photoelectric response type organic-inorganic hybrid complex as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of photoelectric functional materials, and relates to a photoelectric response type organic-inorganic hybrid complex, and the molecular formula of the complex is C40H27InN5O16. According to the compound, photoactive 1, 1 '-bis (4-carboxyl phenyl)-4, 4'-dipyridyl is used as a main ligand, electron-rich terephthalic acid is used as an auxiliary ligand, and the main ligand and In (NO3) 3 are coordinated under the solvothermal condition to form a three-dimensional frame structure. Compared with reported similar compounds, the complex has a sensitive photochromic / electrochromic behavior, changes from orange red to green within 4 seconds after ultraviolet irradiation, and can recover to the initial color after 1 hour after color change. In addition, the compound also shows excellent electrochromism and ammonia gas recognition behaviors with naked eyes. Due to the characteristics, the compound has wide application prospects in the fields of inkless printing, electrochromic devices, photochromic decoration, optical memories, optical switches, photoelectric display, volatile amine detection and the like.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of photoelectric functional materials, and relates to a photoelectric response type organic-inorganic hybrid complex as well as a preparation method and application thereof. BACKGROUND

[0002] Photoelectric chromic materials are intelligent materials capable of reversible color change under the stimulation of light or electricity, and are widely used in fields such as smart windows, displays, anti-glare rearview mirrors, photoelectric sensors, etc. In recent years, with the increasing demand for energy saving, environmental protection and intelligence, photoelectric chromic materials have attracted extensive attention. Traditional photoelectric chromic materials are mainly divided into two categories: inorganic materials and organic materials, but each of them has certain limitations.

[0003] Traditional inorganic photoelectric chromic materials (such as WO3, TiO2) have high chemical and thermal stability, but slow response speed, poor processing performance and single color, which are difficult to meet the diversified application requirements; traditional organic photoelectric chromic materials (such as polyaniline, viologen compounds) have the advantages of fast response speed, adjustable color and good processing performance, but poor stability, low mechanical strength and environmental sensitivity. In order to overcome the limitations of single inorganic or organic materials, researchers have developed inorganic-organic hybrid photoelectric chromic materials. This kind of material combines the high stability of inorganic materials with the fast response and easy processing of organic materials, and exhibits excellent comprehensive performance. However, the existing inorganic-organic hybrid photoelectric chromic materials have single function, which is difficult to meet the multiple application requirements. SUMMARY

[0004] The present application provides a photoelectric response type organic-inorganic hybrid complex, which has good stability, can change from orange red to green within 4s of ultraviolet light irradiation, has a greatly improved photochromic rate, and has a wide application prospect.

[0005] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0006] In a first aspect, the present application provides a photoelectric response type organic-inorganic hybrid complex, wherein the molecule of the complex is C 40 H 27 InN5O 16 , which belongs to triclinic system, P-1 space group, and the unit cell parameters are α = 96.122 (4) °, β = 98.559 (4) °, γ = 105.469 (6) °, and the asymmetric unit contains a half main ligand 1,1'-bis (4-carboxylphenyl) -4,4'-bipyridine, a half auxiliary ligand terephthalic acid, two free nitrate ions and two free water molecules, and each In3+ The six oxygen atoms from three different primary ligands 1,1'-bis(4-carboxyphenyl)-4,4'-bipyridine and two oxygen atoms from a secondary ligand terephthalic acid form an octahedral square antiprism configuration; the three-dimensional structure is constructed as follows: 1,1'-bis(4-carboxyphenyl)-4,4'-bipyridine is connected to two adjacent In 3+ The ions form a one-dimensional zigzag chain, and then the adjacent one-dimensional zigzag chains are connected by another molecule 1,1'-bis(4-carboxyphenyl)-4,4'-bipyridine to form a two-dimensional network structure, and finally the adjacent two-dimensional network structures are connected by the secondary ligand terephthalic acid to form a three-dimensional hole framework structure, and the nitrate ions are connected to the three-dimensional hole framework structure by hydrogen bonding.

[0007] In the technical scheme, under excitation of 365nm ultraviolet light, the crystal color of the complex realizes a change from orange red to green within 4s, and returns to the initial color after 1h. The photochromic principle is mainly caused by the generation of the viologen radical in the electron transfer process.

[0008] In a second aspect, the application further provides a preparation method of the photoelectric response type organic-inorganic hybrid complex, comprising the following steps: uniformly mixing an indium salt, 1,1'-bis(4-carboxyphenyl)-4,4'-bipyridine (abbreviated as bcbp), terephthalic acid (abbreviated as BDC), water, N,N'-dimethylacetamide (abbreviated as DMA) and acetonitrile, and reacting to obtain orange red crystals, which are photo response type complexes.

[0009] In the technical scheme, the indium salt is indium nitrate.

[0010] In the technical scheme, the mass ratio of the indium salt, 1,1'-bis(4-carboxyphenyl)-4,4'-bipyridine and terephthalic acid is 4:1:1.

[0011] In the technical scheme, the volume ratio of the water, N,N'-dimethylacetamide and acetonitrile is 1:1:4.

[0012] In the technical scheme, the reaction temperature is 120℃, and the reaction time is 24-72h.

[0013] In a third aspect, the application further provides an application of the photoelectric response type organic-inorganic hybrid complex in photo / electrochromic products.

[0014] The photo / electrochromic product includes an inkless printing device, an electrochromic device, a photochromic decoration, a photo storage device, a photo switch and a photoelectric display device.

[0015] In a fourth aspect, the application also provides application of the photo / electro responsive organic-inorganic hybrid complex in volatile amine detection.

[0016] Compared with the prior art, the application has the following advantages:

[0017] The application uses photoactive 1,1'-bis(4-carboxylphenyl)-4,4'-bipyridine as a main ligand, and electron-rich terephthalic acid as an auxiliary ligand, and is coordinated with In(NO3)3 under a solvent thermal condition to form a three-dimensional framework structure organic-inorganic hybrid complex, which has photo / electrochromic characteristics, can change from orange red to green in 4s under ultraviolet light, and can basically restore the original state in only 1h.

[0018] The complex of the application can show different color changes when exposed to steam of different volatile amines, especially the most sensitive to ammonia steam, and can be made into a portable test strip for conveniently detecting volatile amines. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 Asymmetric unit diagram of compound 1(a) and compound 2(b) obtained in example 1 of the application.

[0020] Figure 2 Crystal structure diagram of compound 1 obtained in example 1 of the application, wherein Figure 2 a is a one-dimensional chain in compound 1; Figure 2 b is a two-dimensional network structure formed by coordination of bcbp and metal In; Figure 2 c is a three-dimensional framework structure; the round ball in the diagram represents a larger cavity of compound 1.

[0021] Figure 3 Crystal structure of compound 2 obtained from Example 1 of the present application. Figure 3 a is the inorganic one-dimensional chain structure in compound 2; Figure 3 b is the inorganic two-dimensional network structure in compound 2; Figure 3 c is the three-dimensional framework structure formed in compound 2; the green polyhedron in the figure represents the coordination polyhedron of In and oxygen atoms.

[0022] Figure 4 Thermogravimetric analysis of compound 1 (a) and compound 2 (b) obtained from Example 1 of the present application.

[0023] Figure 5 Photochromic pictures of compound 1 (a) and compound 2 (b) obtained from Example 1 of the present application over time.

[0024] Figure 6 Color change contrast of compound 1 and compound 2 obtained from Example 1 of the present application under UV light, wherein the body part is compound 1 and the wing part is compound 2.

[0025] Figure 7 Infrared spectra of compound 1 (a) and compound 2 (b) obtained from Example 1 of the present application before and after light irradiation.

[0026] Figure 8 Powder diffraction patterns of compound 1 (a) and compound 2 (b) obtained from Example 1 of the present application before and after light irradiation.

[0027] Figure 9 Solid-state diffuse reflectance spectra of compound 1 (a) and compound 2 (b) obtained from Example 1 of the present application over time of light irradiation.

[0028] Figure 10 EPR of compound 1 (a) and compound 2 (b) obtained from Example 1 of the present application before and after light irradiation.

[0029] Figure 11 Cyclic voltammogram and electrochromic pictures of compound 1 (a) and compound 2 (b) obtained from Example 1 of the present application.

[0030] Figure 12 Solid-state diffuse reflectance spectra of compound 1 (a) and compound 2 (b) obtained from Example 1 of the present application over voltage change.

[0031] Figure 13 Color change pictures of compound 1 before and after contacting with different amines.

[0032] Figure 14 X-ray powder diffraction patterns of compound 1 before and after contacting with different amines.

[0033] Figure 15 The solid diffuse reflectance spectra of compound 1 obtained in Example 1 of this invention before and after contact with different amines are shown.

[0034] Figure 16 This is a color change graph of compound 1 obtained in Example 1 of the present invention as the concentration of NH3 changes.

[0035] Figure 17 This is a solid-state diffuse reflectance spectrum of compound 1 obtained in Example 1 of the present invention as a function of NH3 concentration.

[0036] Figure 18 The EPR of compound 1 obtained in Example 1 of this invention before and after contact with NH3 is shown. Detailed Implementation

[0037] The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of protection of the present invention. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art. Unless otherwise specified, the test methods in the following embodiments are conventional methods.

[0038] Example 1

[0039] 1,1'-bis(4-carboxyphenyl)-4,4'-bipyridine (bcbp, 10 mg), terephthalic acid (BDC, 10 mg), indium nitrate (40 mg), H2O (1 mL), DMA (1 mL), and CH3CN (4 mL) were added sequentially to a glass bottle, mixed thoroughly, and sealed. The mixture was then reacted in an oven at 120 °C for 36 h. After the reaction was complete, the glass bottle was gradually cooled to room temperature and removed. The crystals formed in the glass bottle were removed to obtain orange-red blocky crystals, which were designated as compound 1, with a yield of 48.9%.

[0040] 1,1'-bis(4-carboxyphenyl)-4,4'-bipyridine (bcbp, 10 mg), anhydrous oxalic acid (20 mg), indium nitrate (25 mg), H2O (1 mL), DMA (2 mL), CH3CN (3 mL), and concentrated hydrochloric acid (300 μL) were added sequentially to a glass bottle, mixed thoroughly, and sealed. The mixture was then reacted in an oven at 120 °C for 36 h. After the reaction was complete, the glass bottle was gradually cooled to room temperature and removed. The crystals formed in the glass bottle were removed to obtain reddish-brown blocky crystals, designated as compound 2, with a yield of 62.7%.

[0041] (1) Elemental analysis (calculated values, %): Compound 1: C 50.65, H 2.87, N 7.38; Compound 2: C 39.33, H 1.98, N 3.06.

[0042] (2) Crystal structure characterization: select a single crystal of appropriate size to carry out X-ray diffraction analysis on Bruker D8 Venture_Air diffractometer, and the test temperature is 298.15 K. MoKα ray is used Collect the crystal diffraction point data, and reduce and absorb the correction of the data by direct method. The structure is analyzed and refined by SHELXT and SHELXL program method. The coordinates of non-hydrogen atoms in the structure are corrected by anisotropic temperature factor by full matrix least squares method, and the coordinates of hydrogen atoms are obtained by difference Fourier synthesis method. The crystallographic data of compound 1 and compound 2 are shown in Table 1.

[0043] Table 1 Crystallographic data of compound 1 and compound 2

[0044]

[0045]

[0046] X-ray single crystal diffraction results show that: compound 1 belongs to triclinic system, P-1 space group. Its asymmetric unit contains a half main ligand bcbp, a half auxiliary ligand BDC, two free NO3 - and two free water molecules Figure 1 a). In the structure, each In 3+ is coordinated with six oxygen atoms from three different main ligands bcbp and two oxygen atoms of the terephthalic acid auxiliary ligand to form an eight-coordinated square antiprism configuration. bcbp connects two adjacent In 3+ ions in a bridging manner to form a one-dimensional zigzag chain Figure 2 a), and then the adjacent one-dimensional zigzag chains are connected by another molecule bcbp to form a two-dimensional network structure Figure 2 b). Finally, adjacent two-dimensional network structures are connected by auxiliary ligand terephthalic acid to form a three-dimensional hole framework structure Figure 2 c). Counterion nitrate ion is connected to the three-dimensional hole framework structure by hydrogen bonding.

[0047] The asymmetric unit of compound 2 contains one bcbp ligand, three auxiliary ligands oxalic acid, two independent metal In ions, and a half free water molecule Figure 1 b). Among them, the metal center In 3+ has a seven-coordinated coordination environment: of the seven oxygen atoms, 1 comes from 1 bcbp ligand, and the remaining six come from 3 auxiliary ligands oxalic acid. In the structure, one molecule of auxiliary ligand oxalic acid connects two adjacent In 3+ ions in a bidentate chelating manner to form a one-dimensional zigzag chain Figure 3a) and then the two-dimensional network structure is cross-linked between adjacent two-dimensional network structures by ligand bcbp to form a three-dimensional supramolecular structure (c). Figure 3 b). Finally, the adjacent two-dimensional network structures are cross-linked by ligand bcbp to form a three-dimensional supramolecular structure (c). Figure 3 c).

[0048] (3) Thermogravimetric analysis: from Figure 4 It can be seen that: compound 1 and compound 2 can be stable to 350℃, and the water removed before 350℃ is physically adsorbed water, indicating that compound 1 and compound 2 both have good thermal stability.

[0049] Example 2 Photochromic experiment

[0050] The block crystals of compound 1 and compound 2 prepared in Example 1 were placed under a microscope using a 365nm ultraviolet lamp, and the color change was observed. As shown in Figure 5 , after irradiation for 4s at room temperature, the color of the crystal of compound 1 changed from orange red to green, and after irradiation for 30s, the color of the crystal changed to dark green and basically reached saturation, and basically faded after being placed in air for 1h (see Figure 5 a); while compound 2 faded more slowly and still had no obvious fading after 4h (see Figure 5 b).

[0051] From the infrared spectrum of Figure 6 , it can be seen that: the ultraviolet irradiation time is 3min, and the infrared spectra of the samples of compound 1 and compound 2 before and after irradiation are similar in peak position, indicating that the structure of the crystal has not changed before and after irradiation.

[0052] From the infrared spectrum of Figure 7 , it can be seen that: the ultraviolet irradiation time is 3min, and the infrared spectra of the samples of compound 1 and compound 2 before and after irradiation are similar in peak position, indicating that the structure of the crystal has not changed before and after irradiation.

[0053] From the powder diffraction pattern of Figure 8 , it can be seen that: the ultraviolet irradiation time is 3min, and the powder diffraction patterns of the samples of compound 1 and compound 2 before and after irradiation are similar in peak position, indicating that the structure of the crystal has not changed before and after irradiation.

[0054] From the irradiation time-dependent solid-state diffuse reflectance spectrum of Figure 9 , it can be seen that: compound 1 and compound 2 have a strong absorption band below 410nm, and a shoulder band appears around 450nm, which is because the π-π* and n-π* transitions of the conjugated ligand bcbp and In 3+Charge transfer between ions and bcbp ligands. After UV irradiation, three new absorption peaks appeared near 450 nm, 670 nm and 740 nm, and the intensity gradually increased with the extension of irradiation time and tended to be saturated after 60 s of irradiation.

[0055] From Figure 10 EPR analysis can be seen: before light compound 1 and compound 2 have no free radical signal, and after 3 min of ultraviolet light, the sample appears obvious singlet free radical signal peak near g = 2.004, indicating that there is viologen radical generation.

[0056] Example 3 electrochromic experiment.

[0057] 10 mg of compound 1 and compound 2 prepared in example 1 were added to the mixed solution of 0.2 mL PMMA solution and 0.2 mL anhydrous ethanol, and ultrasonic for 30 min until the compound was uniformly dispersed in the solution. The solution was packaged into an electrochromic device (the electrochromic device contains two pieces of ITO conductive glass, the solution is coated between the two pieces of ITO conductive glass, and naturally air dried to obtain the electrochromic device. After the electrochromic device is powered under a certain voltage (0~ -0.6V), the color change is observed. As shown in Figure 11 , the electrochromic device changes from brown to green, and the cyclic voltammetry curves of compound 1 and compound 2 both appear two redox peaks at -0.41V and -0.48V, -0.59V and -0.92V. And from Figure 12 the solid-state diffuse reflectance spectrum can be seen: with the increase of voltage, the intensity of the absorption peak is also gradually increased.

[0058] Example 4 volatile amine detection

[0059] 5 mg of compound 1 prepared in example 1 was added to a 2 mL glass bottle, and the glass bottle was sealed in a 20 mL glass bottle containing 1 mL of different amine (ammonia, ethylamine, propylamine, dimethylamine, diethylamine), and the color change of the sample was observed. As Figure 13 can be seen, the change from orange red to brown or dark green is realized within 3 s, which shows high sensitivity and fast response of gas sensing characteristics, especially ammonia vapor is the most sensitive.

[0060] Figure 14 X-ray powder diffraction patterns of compound 1 before and after contacting with different amines. It can be seen that the X-ray powder diffraction patterns of the samples before and after contacting with different amines have similar peak positions compared with the X-ray powder diffraction pattern of compound 1, which shows that the crystal structure of compound 1 has not changed before and after contacting with different amines.

[0061] Figure 15The solid-state diffuse reflectance spectra of compound 1 before and after contacting with different amines. It can be seen that the solid-state diffuse reflectance spectra of compound 1 after contacting with different amines have similar peak positions compared with the light-dependent solid-state diffuse reflectance spectra, indicating that the color change of compound 1 in recognizing different volatile amines is consistent with the mechanism of photochromism.

[0062] Figure 16 The color change graph of compound 1 with the change of NH3 concentration. It can be seen that when the NH3 concentration is less than or equal to 1%, the compound almost does not appear color change; but when the NH3 concentration is between 5%-25%, with the increase of the concentration of ammonia, the color of compound 1 gradually deepens, indicating that the compound 1 can recognize low concentration of volatile amine.

[0063] Figure 17 The solid-state diffuse reflectance spectra of compound 1 with the change of NH3 concentration. It can be seen that when the ammonia concentration is between 5%-25%, new absorption peaks appear near 590nm, 670nm, 740nm, and with the increase of the concentration of ammonia, the intensity of these absorption peaks also increases. This proves that free radicals are generated in the color change process of compound 1 binding volatile amines, and with the increase of the concentration of volatile amines, the number of free radicals also increases.

[0064] Figure 18 The EPR of compound 1 before and after contacting with NH3. It can be seen that compound 1 exhibits a weak free radical signal before contacting with NH3, and after contacting with NH3, it presents a high intensity and center-symmetric signal, which indicates that free radicals exist in the sample after contacting with NH3.

[0065] The above-described embodiments are only preferred embodiments of the present application, merely used to explain the present application, and are not intended to limit the scope of the present application. For those skilled in the art, of course, other embodiments can be easily made by substitution or change based on the technical content disclosed in the present specification, and therefore, any changes and improvements made on the principles of the present application shall be included in the scope of the present application.

Claims

1. A photoelectric response type organic-inorganic hybrid complex, characterized by, The molecular formula of the complex is C 40 H 27 InN5O 16 , belongs to triclinic system, P -1 space group, the cell parameters are a = 9.7078(6) Å, b = 14.3434(10) Å, c = 16.2881(6) Å, α = 96.122(4) °, β = 98.559(4) °, γ = 105.469(6) °, and the asymmetric unit contains one half of the main ligand 1,1'-bis(4-carboxyphenyl)-4,4'-bipyridine, one half of the auxiliary ligand terephthalic acid, two free nitrate ions and two free water molecules, each In 3+ coordinates with six oxygen atoms from three different main ligands 1,1'-bis(4-carboxyphenyl)-4,4'-bipyridine and two oxygen atoms from the auxiliary ligand terephthalic acid to form an eight-coordinated square antiprism configuration; the three-dimensional structure is constructed as follows: 1,1'-bis(4-carboxyphenyl)-4,4'-bipyridine connects two adjacent In 3+ ions in a bridging manner to form a one-dimensional zigzag chain, then the adjacent one-dimensional zigzag chains are connected by another molecule of 1,1'-bis(4-carboxyphenyl)-4,4'-bipyridine to form a two-dimensional network structure, and finally the adjacent two-dimensional network structures are connected by the auxiliary ligand terephthalic acid to form a three-dimensional hole framework structure, and the nitrate ions are connected to the three-dimensional hole framework structure by hydrogen bonding. 2.The photoelectric response type organic-inorganic hybrid complex according to claim 1, characterized in that, The crystal color of the complex realizes a transition from orange red to green within 4 s under 365 nm ultraviolet light excitation, and returns to the initial color after 1 h.

3. The method for preparing the photoresponsive organic-inorganic hybrid complex according to any one of claims 1 to 2, characterized by, The method comprises the following steps: The indium salt, 1,1'-bis(4-carboxyphenyl)-4,4'-bipyridine, terephthalic acid, water, N,N'-dimethylacetamide and acetonitrile are uniformly mixed to react, and orange red crystals are obtained.

4. The method for preparing photoelectric response type organic-inorganic hybrid complex according to claim 3, characterized in that, The indium salt is indium nitrate.

5. The method for preparing photoelectric response type organic-inorganic hybrid complex according to claim 3, characterized in that, The mass ratio of the indium salt, 1,1'-bis(4-carboxyphenyl)-4,4'-bipyridine and terephthalic acid is 4:1:

1. 6.The method for preparing a photoelectric response type organic-inorganic hybrid complex according to claim 4, characterized in that, The volume ratio of the water, N,N'-dimethylacetamide and acetonitrile is 1:1:

4.

7. The method for preparing photoelectric response type organic-inorganic hybrid complex according to claim 4, characterized in that, The reaction temperature is 120 DEG C, and the reaction time is 24-72 h.

8. Application of the photoelectric response type organic-inorganic hybrid complex according to any one of claims 1-2 to photo / electrochromic products.

9. Application of the photoelectric response type organic-inorganic hybrid complex according to any one of claims 1-2 to volatile amine detection.

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