Organic metal ion salt room-temperature phosphorescent crystal material as well as preparation method and application thereof
By preparing room temperature phosphorescence crystal materials of organic metal ion salts, the coordination reaction between heterocyclic organic small molecules and inorganic metal salts is used to solve the problem of insufficient phosphorescence in the organic ion salt system, and the ultra-long luminescence life and high stability are achieved, which is suitable for pattern display.
Patent Information
- Application Number
- CN202510418883.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-03
- Publication Date
- 2025-08-12
AI Technical Summary
The prior art is difficult to achieve room temperature phosphorescence in organic ion salt systems, mainly because weak spin orbit coupling in pure organic materials hinders the generation of phosphorescence and lacks a high-performance organic metal ion salt system.
By using heterocyclic organic small molecules containing two carboxyl groups to coordinate with the inorganic metal salt, an organic metal ion salt room temperature phosphorescence crystal material is prepared by hydrothermal method, heavy metal ions are introduced to promote the transition from singlet excitons to triplets, and molecular movement is restricted through ionic bonds.
An organic metal ion salt room temperature phosphorescence crystal material with ultra-long luminescence life and high stability was prepared, suitable for pattern long afterglow display.
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Figure CN120463648A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of organic-inorganic hybrid long afterglow materials, and specifically relates to the preparation of an organic ion salt room temperature phosphorescent crystal material with an ultra-long phosphorescence lifetime, and to the application of such material in pattern display. Background Art
[0002] Researchers generally use strategies such as eutectics, host-guest doping, and H-type aggregation to extend the lifetime of room-temperature phosphorescence. For example, crystal engineering and host-guest systems can not only effectively protect triplet excitons from quenching by oxygen and moisture, but also restrict the rotation and vibration of molecules, significantly extending the phosphorescence lifetime. Great achievements have been made in improving the performance of room-temperature phosphorescence, but the inherently weak spin-orbit coupling (SOC) in pure organic materials hinders the generation of room-temperature phosphorescence. Therefore, it is difficult to generate room-temperature phosphorescence in metal-free materials. By introducing heavy atoms (such as Ca, Mg, etc.), SOC can be promoted, thereby facilitating the transition of singlet excitons from the singlet excited state to the triplet excited state.
[0003] Organic-inorganic hybrid materials with long-lasting room-temperature phosphorescence (RTP) have attracted significant interest due to their potential applications in advanced data encryption and anti-counterfeiting, bioimaging, high-sensitivity sensors, and persistent organic light-emitting diodes (OLEDs). Currently, a range of high-performance RTP organic-inorganic hybrid luminescent materials has been designed and prepared by constructing organic ionic crystals, coordination polymers, and metal-organic framework crystals. While tunable phosphorescent emission colors have been successfully achieved, organic ionic salt systems exhibiting RTP remain lacking.
[0004] Ionic bonds not only have strong interactions, but also have unique properties of being non-directional and unsaturated. Ionic bonding in organic ionic crystals can restrict the rotation and vibration of molecules, thereby reducing the non-radiative transition of triplet excitons. To obtain room temperature phosphorescence in an organic ionic salt system, one can first introduce heavy metal ions. Due to the heavy atom effect, the transition of excitons from singlet to triplet states is enhanced. In addition, the introduction of organic small molecules containing phosphorescent chromophores can provide triplet excitons, and the ionic bonds formed with metals can further restrict the movement of organic chromophores, thereby inhibiting the non-radiative transition of triplet excitons, promoting the emission of room temperature phosphorescence, and realizing organic metal ion salt room temperature phosphorescent crystal materials. Summary of the Invention
[0005] The purpose of the present invention is to provide an organic metal ion salt room temperature phosphorescent crystal material with ultra-long luminescence lifetime and a preparation method thereof. The material has important properties such as ultra-long luminescence lifetime and high stability, and can be applied to pattern long afterglow display.
[0006] To achieve the above object, the present invention adopts the following technical solutions:
[0007] A room-temperature phosphorescent crystal material of an organic metal ion salt with an ultra-long luminescence lifetime is prepared by a hydrothermal method using a heterocyclic organic small molecule containing two carboxyl groups as an organic ligand coordinated with an inorganic metal salt.
[0008] Furthermore, the molar ratio of the heterocyclic organic small molecule containing two carboxyl groups to the inorganic metal salt is 1:1.8-2.2, preferably 1:2.
[0009] Furthermore, the heterocyclic organic small molecule containing two carboxyl groups is any one of the following structural formulas:
[0010]
[0011] Furthermore, the inorganic metal salt is any one of the following structural formulas:
[0012] Zn(NO3)2·6H2O, Cd(NO3)2·4H2O, Ca(NO3)2·4H2O, Mg(NO3)2·4H2O, MgCl2, CaCl2, etc.
[0013] Furthermore, the preparation method of the organic metal ion salt room temperature phosphorescent crystal material is as follows: a heterocyclic organic small molecule containing two carboxyl groups and an inorganic metal salt are added to deionized water, heated at 115-125°C for 22-26 hours, cooled to room temperature, filtered and dried to obtain the organic metal ion salt room temperature phosphorescent crystal material.
[0014] Furthermore, the luminescence lifetime of the organic metal ion salt room temperature phosphorescent crystal material reaches more than 545 ms, and even up to 700 ms, and can be applied to pattern long afterglow display.
[0015] The present invention characterizes the structure of organic metal ion salt room temperature phosphorescent crystal materials by single crystal X-ray diffraction; through the measurement of fluorescence emission spectrum and phosphorescence lifetime, the photophysical properties of this series of organic metal ion salt room temperature phosphorescent crystal materials at room temperature are studied in detail. By changing different inorganic metal salts, the dipole moment of the molecules is changed, and the stacking mode of the molecules is controlled to achieve the regulation of the photophysical properties.
[0016] Compared with the prior art, the beneficial effects of the present invention are: the preparation method of the present invention is simple, the raw materials are cheap, and the obtained long-afterglow metal ion salt material has the characteristics of ultra-long luminescence life and good stability, and can be used for pattern long-afterglow display. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 The phosphorescence spectra of the organic metal ion salt room temperature phosphorescent crystal materials prepared in Examples 1 and 2 are shown.
[0018] Figure 2 Predicted and experimental PXRD spectra of the organic metal ion salt phosphorescent crystal materials prepared in Examples 1 and 2.
[0019] Figure 3 These are graphs showing the luminescence of the organic metal ion salt room temperature phosphorescent crystal materials prepared in Examples 1 and 2 under natural light, ultraviolet light, and after irradiation.
[0020] Figure 4 This is a room temperature lifetime decay curve of the organic metal ion salt room temperature phosphorescent crystal material prepared in Examples 1 and 2.
[0021] Figure 5 These are luminescence diagrams of the organic metal ion salt room temperature phosphorescent crystal materials prepared in Examples 1 and 2, which were prepared into patterns of different shapes under and after irradiation with a 365nm ultraviolet lamp. DETAILED DESCRIPTION
[0022] In order to make the contents of the present invention easier to understand, the technical solutions of the present invention are further described below in conjunction with specific embodiments, but the present invention is not limited thereto.
[0023] Example 1
[0024] The heterocyclic organic small molecule containing two carboxyl groups used in this embodiment is 2-bromo-1H-imidazole-4,5-dicarboxylic acid (Hbridc), and the reaction formula is as follows:
[0025]
[0026] 117.5 mg (0.5 mmol) of 2-bromo-1H-imidazole-4,5-dicarboxylic acid, 236.2 mg (1 mmol) of Ca(NO3)2·4H2O, and 41 mg (0.5 mmol) of 2-methylimidazole (MIM) were weighed into a polytetrafluoroethylene liner, 5 mL of deionized water was added, and the mixture was heated to 120°C for 24 h. After the reaction was completed, the mixture was slowly restored to room temperature, filtered, and dried in an oven at 50°C to obtain 2-bromo-1H-imidazole-4,5-dicarboxylic acid metal ion crystals (Ca-bridc).
[0027] Example 2
[0028] The heterocyclic organic small molecule containing two carboxyl groups used in this embodiment is 2-amino-4,5-imidazoledicarboxylic acid (HAidc), and the reaction formula is as follows:
[0029]
[0030] Weigh 85.5 mg (0.5 mmol) of 2-amino-4,5-imidazoledicarboxylic acid, 95.21 mg (1 mmol) of MgCl2, and 41 mg (0.5 mmol) of 2-methylimidazole (MIM) into a polytetrafluoroethylene liner. Add 5 mL of deionized water and heat to 120°C for 24 hours. After the reaction is complete, slowly return to room temperature, collect by filtration, and dry in an oven at 50°C to obtain 2-amino-4,5-imidazoledicarboxylic acid metal ion crystals (Mg-Aidc).
[0031] Figure 1 The phosphorescence spectra of the organometallic ion salt room temperature phosphorescent crystal materials prepared in Examples 1 and 2 are shown in FIG. As can be seen from the figure, the phosphorescence spectrum peaks of the organometallic ion salt materials prepared in Examples 1 and 2 are located at 512 nm and 508 nm, respectively.
[0032] Figure 2 The PXRD spectra of the organometallic ion salt room temperature phosphorescent crystal materials prepared in Examples 1 and 2 are shown in FIG. As can be seen from the figure, the predicted PXRD spectra are basically consistent with those prepared experimentally.
[0033] Figure 3 The following graphs show the luminescence of the organometallic ion salt room temperature phosphorescent crystalline materials prepared in Examples 1 and 2 under natural light, UV light, and after exposure. As can be seen from the graphs, the organometallic ion salt room temperature phosphorescent crystalline materials prepared in Examples 1 and 2 emit blue fluorescence under 365nm UV light. After turning off the UV light, a green afterglow color, indicating room temperature phosphorescence, can be observed.
[0034] Figure 4 The room temperature lifetime decay curves of the organometallic ion salt room temperature phosphorescent crystal materials prepared in Examples 1 and 2 are shown. The lifetimes of the phosphorescence emission peaks were monitored and the corresponding lifetime decay curves were plotted, showing that the room temperature phosphorescence lifetimes reached 545ms and 700ms, respectively.
[0035] Example 3
[0036] In view of the fact that the 2-bromo-1H-imidazole-4,5-dicarboxylic acid metal ion crystal prepared in Example 1 has the characteristics of ultra-long room temperature phosphorescence, the present invention further demonstrates its application in long afterglow display. First, grind the Ca-bridc room temperature phosphorescent material obtained in Example 1, grind the material into powder and mix it with PMMA as a long afterglow flexible liquid, and prepare "I" through template. "O" pattern, e.g. Figure 5 As shown, under 365nm ultraviolet light, blue letter patterns are displayed, and when the ultraviolet light is turned off, green letter patterns are displayed.
Claims
1. An organic metal ion salt room temperature phosphorescent crystal material, characterized in that: It is prepared by a hydrothermal method using a heterocyclic organic small molecule containing two carboxyl groups as an organic ligand, coordinated with an inorganic metal salt.
2. The organic metal ion salt room temperature phosphorescent crystal material according to claim 1, characterized in that: The heterocyclic organic small molecule containing two carboxyl groups is any one of the following structural formulas:
3. The organic metal ion salt room temperature phosphorescent crystal material according to claim 2, characterized in that: The heterocyclic organic small molecule containing two carboxyl groups is pyrazine-2,3-dicarboxylic acid or 5-methylpyrazine-2,3-dicarboxylic acid.
4. The organic metal ion salt room temperature phosphorescent crystal material according to claim 1, characterized in that: The inorganic metal salt is any one of the following structural formulas: Zn(NO3)2·6H2O, Cd(NO3)2·4H2O, Ca(NO3)2·4H2O, Mg(NO3)2·4H2O, MgCl2, CaCl2.
5. The organic metal ion salt room temperature phosphorescent crystal material according to claim 1, characterized in that: Its luminous lifetime reaches more than 545ms.
6. The method for preparing an organic metal ion salt room temperature phosphorescent crystal material according to any one of claims 1 to 5, characterized in that: A heterocyclic organic small molecule containing two carboxyl groups and an inorganic metal salt are added to water, heated at 115-125° C. for 22-26 hours, cooled to room temperature, filtered and dried to obtain an organic metal ion salt room temperature phosphorescent crystal material.
7. The method for preparing an organic metal ion salt room temperature phosphorescent crystal material according to claim 6, characterized in that: The molar ratio of the heterocyclic organic small molecule containing two carboxyl groups to the inorganic metal salt is 1:1.8-2.
2.
8. The method for preparing an organic metal ion salt room temperature phosphorescent crystal material according to claim 7, characterized in that: The molar ratio of the heterocyclic organic small molecule containing two carboxyl groups to the inorganic metal salt is 1:1.8-2.
2.
9. Use of the organic metal ion salt room temperature phosphorescent crystal material according to any one of claims 1 to 5 in pattern long afterglow display.