A cadmium metal-organic framework material with long afterglow characteristics, preparation method and application

Abstract

The invention discloses a cadmium metal-organic framework material with long afterglow characteristics, a preparation method and an application thereof, and belongs to the field of metal-organic framework crystalline functional materials. The chemical formula of the complex is [Cd2(D-Cam)2(bidpe)2]·6H2O, wherein bidpe is 4,4'-bis(imidazole-1-yl)diphenyl ether, and D-Cam is deprotonated D-camphoric acid. The preparation method is as follows: under solvent-thermal conditions, a mixed solvent of cadmium nitrate, 4,4'-bis(imidazole-1-yl)diphenyl ether, D-camphoric acid, N,N'-dimethylformamide (DMF) and water is added to a reactor containing a polytetrafluoroethylene liner, reacted at 120°C for 48h, cooled, washed and dried; the preparation method of the invention is simple, has good stability and high yield; under room temperature conditions, under irradiation with a 365nm ultraviolet lamp, blue fluorescence emission is displayed, and after turning off the ultraviolet light, a relatively long green phosphorescence is displayed.

Description

Technical Field

[0001] The invention relates to the field of metal-organic framework crystalline functional materials, and in particular provides a cadmium metal-organic framework material with long afterglow characteristics and a preparation method and application thereof. Background Art

[0002] So far, the research on inorganic long afterglow materials has been very mature, but the preparation process of inorganic long afterglow materials is relatively complicated and the materials used are relatively expensive. Compared with inorganic long afterglow materials, organic room temperature phosphorescent materials have attractive application prospects in many high-tech fields such as biological imaging, optical recording, information storage, anti-counterfeiting systems, etc. due to their advantages such as low price, simple synthesis, good biocompatibility, flexibility and easy functional group modification. Summary of the invention

[0003] The object of the present invention is to provide a cadmium metal-organic framework material with long afterglow characteristics and a preparation method thereof. The raw materials for the synthesis of the material are easily available, the preparation method is simple, the stability is good, and the yield is high. The phosphorescence life is long, and the material has broad application prospects in the field of fluorescent and phosphorescent materials.

[0004] The invention provides a cadmium metal-organic framework material with a long afterglow characteristic. The chemical formula of the material complex is: [Cd2(D-Cam)2(bidpe)2]·6H2O, wherein bidpe is 4,4'-bis(imidazole-1-yl)diphenyl ether, and D-Cam is deprotonated D-camphoric acid.

[0005] The cadmium complex belongs to the monoclinic system, the space group is P21, and the crystal parameters are α=90°, β=113.460(7)°, γ=90°, Z=2,

[0006] The crystallographic data of the cadmium metal-organic framework material with long afterglow characteristics provided by the present invention are shown in Table 1.

[0007] Table 1 Crystallographic data of cadmium metal-organic framework materials

[0008]

[0009]

[0010] The present invention provides a method for preparing the above-mentioned cadmium metal-organic framework material with long afterglow characteristics, and the reaction steps are as follows:

[0011] Under nitrogen protection, 4,4'-dibromodiphenyl ether, imidazole, K2CO3 and Cu2O are mixed in N,N'-dimethylformamide and heated to reflux at 160°C for 48 hours. After stopping the reaction, cool to room temperature, filter and wash several times until the filtrate becomes a clear liquid, collect the filtrate, pour ice distilled water into the filtrate to produce a white solid, filter and dry to obtain 4,4'-bis(imidazole-1-yl)diphenyl ether. A mixed solvent of 4,4'-bis(imidazole-1-yl)diphenyl ether, D-camphoric acid, cadmium nitrate, N,N'-dimethylformamide (DMF) and water is added to a reactor containing a polytetrafluoroethylene liner and heated for reaction, then cooled, washed and dried to obtain the cadmium-based complex.

[0012] The advantages of the present invention are: the preparation method of the cadmium metal-organic framework material of the present invention is simple, has good stability and high yield. Under room temperature, under 365nm ultraviolet light irradiation, it shows blue fluorescence emission, and after turning off the ultraviolet light, it shows a long green phosphorescence. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is the asymmetric unit structure diagram of the cadmium metal-organic framework material complex of the present invention;

[0014] Figure 2 is a two-dimensional structure diagram of the cadmium metal-organic framework material complex of the present invention;

[0015] Figure 3 It is a stacking diagram of the cadmium metal-organic framework material complex of the present invention;

[0016] Figure 4 It is a comparison diagram of X-ray diffraction and simulated diffraction of the cadmium metal-organic framework material complex of the present invention;

[0017] Figure 5 This is a thermogravimetric analysis diagram of the cadmium metal-organic framework material complex of the present invention;

[0018] Figure 6 The fluorescence and phosphorescence emission spectra of the cadmium metal-organic framework material complex of the present invention;

[0019] Figure 7 The phosphorescence attenuation curve of the cadmium metal-organic framework material complex of the present invention; DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0021] The present invention provides a cadmium metal-organic framework material with long afterglow characteristics. The chemical formula of the complex of the material is: [Cd2(D-Cam)2(bidpe)2]·6H2O, wherein bidpe is 4,4'-bis(imidazole-1-yl)diphenyl ether, and D-Cam is deprotonated D-camphoric acid. The cadmium metal-organic framework material belongs to the monoclinic system, the space group is P21, and the crystal parameters are α=90°, β=113.460(7)°, γ=90°, Z=2,

[0022] In the cadmium metal-organic framework material with long afterglow characteristics of the present invention, Cd 2+ There are two coordination modes, both are six-coordinated, one of which is Cd 2+ Connected to four oxygen atoms (O3, O4, O5 and O6) and two nitrogen atoms (N8 and N1#2), of which the four oxygen atoms (O3, O4, O5 and O6) come from two deprotonated D-camphoric acids, the two nitrogen atoms (N8 and N1#2) come from two bidpe ligands, and the other Cd 2+ Connected to four oxygen atoms (O7, O8, O9 and O10) and two nitrogen atoms (N4 and N5), of which the four oxygen atoms (O7, O8, O9 and O10) come from two deprotonated D-camphoric acids, and the two nitrogen atoms (N4 and N5) come from two bidpe ligands. 2+ Connect to form a chain structure, deprotonated D-camphoric acid and Cd 2+ The two chain structures are connected to form a chain structure, and the two chain structures are then connected to each other to form a two-dimensional network structure.

[0023] Example 1

[0024] 0.0302 g of 4,4'-bis(imidazole-1-yl)diphenyl ether, 0.0200 g of D-camphoric acid and 0.0616 g of cadmium nitrate were dissolved in a mixed solution of N,N'-dimethylformamide and water, wherein the volume ratio of N,N'-dimethylformamide to water was 1:1, and put into a 25 ml polytetrafluoroethylene-lined reactor, and reacted at 100°C for 48 hours. After the reaction was completed, the mixture was naturally cooled to room temperature to obtain colorless block crystals. The colorless block crystals were separated, and washed and dried in sequence to obtain the target product.

[0025] Example 2

[0026] 0.0302g of 4,4'-bis(imidazole-1-yl)diphenyl ether, 0.0200g of D-camphoric acid and 0.0308g of cadmium nitrate were dissolved in a mixed solution of N,N'-dimethylformamide and water, wherein the volume ratio of N,N'-dimethylformamide to water was 1:1, and put into a 25ml polytetrafluoroethylene-lined reactor, and reacted at 85°C for 72 hours. After the reaction was completed, it was naturally cooled to room temperature to obtain colorless block crystals. The colorless block crystals were separated, and washed and dried in sequence to obtain the target product.

[0027] Example 3

[0028] 0.0302 g of 4,4'-bis(imidazole-1-yl)diphenyl ether, 0.0200 g of D-camphoric acid and 0.0616 g of cadmium nitrate were dissolved in a mixed solution of N,N'-dimethylformamide and water, wherein the volume ratio of N,N'-dimethylformamide to water was 1:1, and put into a 25 ml polytetrafluoroethylene-lined reactor, and reacted at 120°C for 48 hours. After the reaction was completed, it was naturally cooled to room temperature to obtain colorless block crystals. The colorless block crystals were separated, and washed and dried in sequence to obtain the target product.

[0029] Example 4

[0030] 0.0302 g of 4,4'-bis(imidazole-1-yl)diphenyl ether, 0.0200 g of D-camphoric acid and 0.0616 g of cadmium nitrate were dissolved in a mixed solution of N,N'-dimethylformamide and water, wherein the volume ratio of N,N'-dimethylformamide to water was 1:1, and put into a 25 ml polytetrafluoroethylene-lined reactor, and reacted at 120°C for 72 hours. After the reaction was completed, it was naturally cooled to room temperature to obtain colorless block crystals. The colorless block crystals were separated, and washed and dried in sequence to obtain the target product.

[0031] Example 5

[0032] 0.0302 g of 4,4'-bis(imidazole-1-yl)diphenyl ether, 0.0200 g of D-camphoric acid and 0.0616 g of cadmium nitrate were dissolved in a mixed solution of N,N'-dimethylformamide and water, wherein the volume ratio of N,N'-dimethylformamide to water was 1:1, and put into a 25 ml polytetrafluoroethylene-lined reactor, and reacted at 110°C for 48 hours. After the reaction was completed, it was naturally cooled to room temperature to obtain colorless block crystals. The colorless block crystals were separated, and washed and dried in sequence to obtain the target product.

[0033] The present invention provides a cadmium metal-organic framework material with long afterglow characteristics. The chemical formula of the complex of the material is: [Cd2(D-Cam)2(bidpe)2]·6H2O, wherein bidpe is 4,4'-bis(imidazole-1-yl)diphenyl ether, and D-Cam is deprotonated D-camphoric acid. The cadmium complex belongs to the monoclinic system, the space group is P21, and the crystal parameters are α=90°, β=113.460(7)°, γ=90°, Z=2,

[0034] Figure 1 is the asymmetric unit structure diagram of the cadmium metal-organic framework material complex of the present invention, consisting of Figure 1 It can be seen that due to the asymmetry of D-camphoric acid, Cd 2+ There are two coordination modes, both of which are hexacoordinated. 2+ Connected to four oxygen atoms (O3, O4, O5 and O6) and two nitrogen atoms (N8 and N1#2), of which the four oxygen atoms (O3, O4, O5 and O6) come from two deprotonated D-camphoric acids, the two nitrogen atoms (N8 and N1#2) come from two bidpe ligands, and the other Cd 2+ It is connected to four oxygen atoms (O7, O8, O9 and O10) and two nitrogen atoms (N4 and N5), of which the four oxygen atoms (O7, O8, O9 and O10) come from two deprotonated D-camphoric acids, and the two nitrogen atoms (N4 and N5) come from two bidpe ligands.

[0035] Figure 2 is a two-dimensional structure diagram of the cadmium metal-organic framework material complex of the present invention, Figure 2 It can be seen that bidpe ligand and Cd 2+ Connect to form a chain structure, deprotonated D-camphoric acid and Cd 2+ The two chain structures are connected to form a chain structure, and the two chain structures are then connected to each other to form a two-dimensional network structure.

[0036] Figure 3 is a stacking diagram of the cadmium metal-organic framework material complex of the present invention, Figure 3 It can be seen that the two-dimensional network structure is stacked layer by layer.

[0037] Figure 4 is a comparison diagram of the X-ray diffraction and simulated diffraction of the cadmium metal-organic framework material complex of the present invention, Figure 4It can be seen that the powder X-ray diffraction pattern is consistent with the experimental simulation diffraction pattern, indicating that the cadmium metal-organic framework material has reliable phase purity, which provides a guarantee for its application as a long afterglow material.

[0038] Figure 5 is the thermogravimetric analysis diagram of the cadmium metal-organic framework material complex of the present invention, Figure 5 It can be seen that the thermogravimetric analysis characterization of the cadmium metal-organic framework material shows that it remains stable at 290°C and has a certain thermal stability.

[0039] Figure 6 is the fluorescence and phosphorescence emission spectra of the cadmium metal-organic framework material complex of the present invention, Figure 6 It can be seen that the fluorescence emission peak of the cadmium metal-organic framework material complex is around 445nm, showing blue emission, and the phosphorescence emission peak of the complex is around 540nm, showing green emission.

[0040] Figure 7 is the phosphorescence attenuation curve of the cadmium metal-organic framework material complex of the present invention, Figure 7 It can be seen that the phosphorescence lifetime of the cadmium metal-organic framework material is 2650ms. Under room temperature, under 365nm ultraviolet light, it shows blue fluorescence emission. After turning off the ultraviolet light, the cadmium metal-organic framework material emits green phosphorescence visible to the naked eye for several seconds.

Claims

1. A cadmium metal-organic framework material with long afterglow characteristics, characterized in that: The chemical formula of the complex of the material is: [Cd2(D-Cam)2(bidpe)2]•6H2O, wherein bidpe is 4,4'-bis(imidazole-1-yl)diphenyl ether, D-Cam is deprotonated D-camphoric acid, and the complex belongs to the monoclinic system, and the space group is P 21, the crystal parameters are a = 16.6928(10) (2) Å, b = 9.3844(4) Å, c = 19.6627(11) Å, α = 90°, β = 113.460(7)°, γ = 90°, Z = 2, V = 2825.6(3) Å3.

2. The method for preparing a cadmium metal-organic framework material with long afterglow characteristics according to claim 1, characterized in that: The following steps are involved: S1. Under nitrogen protection, 4,4'-dibromodiphenyl ether, imidazole, K2CO3 and Cu2O were mixed in N,N'-dimethylformamide and heated under reflux at 160°C for 48 hours; after stopping the reaction, the mixture was cooled to room temperature, filtered and washed several times until the filtrate became a clear liquid; S2. Collect the filtrate, pour ice distilled water into the filtrate to produce a white solid, filter and dry to obtain 4,4'-bis(imidazol-1-yl)diphenyl ether; S3. Adding a mixed solvent of 4,4'-bis(imidazole-1-yl)diphenyl ether, D-camphoric acid, cadmium nitrate, N,N'-dimethylformamide and water to a reactor containing a polytetrafluoroethylene liner, heating for reaction, cooling, washing and drying to obtain the cadmium metal-organic framework material; The molar ratio of 4,4'-bis(imidazol-1-yl)diphenyl ether, D-camphoric acid and cadmium nitrate is 1:1:1-2; The heating reaction temperature in step S3 is 85-120° C. and the time is 48-72 hours.

3. The use of a cadmium metal-organic framework material with long afterglow characteristics according to claim 1, characterized in that: It can be applied to fluorescent and long-life phosphorescent materials.

Images