Organic luminescent material with visible light excitation and adjustable room temperature phosphorescence characteristics and preparation method thereof

Abstract

The invention belongs to the technical field of organic luminescent materials, and relates to an organic luminescent material with visible light excitation and adjustable room temperature phosphorescence characteristics and a preparation method thereof. According to the method, an aromatic fused ring which does not contain heavy atoms and heteroatoms is taken as a doping object, anthraquinone and derivatives thereof are taken as a host matrix, doping is carried out through a solution volatilization method or a melting cooling method, and the organic luminescent material with visible light excitation and adjustable room temperature phosphorescence characteristics is obtained. Ground state energy transfer between a subject and an object is constructed, so that the material absorbs red and shifts to a visible light region, triplet emission of the subject is excited, an intersystem crossing process of the object is excited, and efficient room-temperature phosphorescence emission of the material under visible light and even white light is realized; the energy transfer intensity between a subject and an object is regulated and controlled by changing the length of a subject alkyl chain, effective adjustment of material phosphorescence from green to red is achieved, and the method has wide application prospects in the fields of information storage, data encryption and counterfeiting prevention, special printing technologies, programmable labels, biological imaging and the like.

Description

Technical Field

[0001] This invention belongs to the field of organic light-emitting materials technology, and relates to an organic light-emitting material with visible light excitation and tunable room temperature phosphorescence properties, and its preparation method. Background Technology

[0002] Organic room-temperature long-afterglow (p-RTP) materials have attracted widespread attention in display technology, sensors, optoelectronic devices, and bioimaging fields due to their long-afterglow luminescence, abundant excited-state characteristics, and superior biocompatibility compared to inorganic systems. However, organic chromophores inherently possess weak spin-orbit coupling (SOC), resulting in low intersystem crossing efficiency from singlet to triplet excitons. Simultaneously, triplet excitons are highly susceptible to nonradiative quenching under room-temperature conditions due to molecular vibrations, oxygen, and impurities. These two core issues directly lead to the generally low luminescence quantum efficiency and short phosphorescence lifetime of traditional organic p-RTP materials, making it difficult to meet the stringent performance requirements of practical applications.

[0003] To overcome these challenges, researchers have employed various strategies, including molecular crystallization, polymerization, self-assembly, and host-guest doping, to enhance p-RTP performance. Despite these advances, most reported systems still rely on ultraviolet light excitation. In contrast, research on systems exciteable by visible light or even natural light remains limited, despite the significant advantages these systems offer in applications—such as greater ease of use, lower phototoxicity, and enhanced light penetration in biological systems.

[0004] Furthermore, existing organic p-RTP systems face the challenge of limited color emission: most reported materials exhibit afterglow emission colors concentrated in the green or yellow bands, lacking multi-color tunable systems covering the blue, green, and red visible light regions. Tunable multi-color long-persistence emission is a core prerequisite for high-end applications such as full-color displays, multi-biomarker imaging, and multi-level information encryption / decryption. This deficiency severely restricts the expansion of application scenarios for organic p-RTP materials.

[0005] Although researchers have attempted to modulate the color of light emission through various strategies, these approaches generally have significant limitations: On the one hand, most strategies can only achieve limited color changes under ultraviolet light excitation, and cannot be adapted to visible light excitation systems, which have greater application value; on the other hand, all kinds of modulation methods have inherent defects: chemical structure modification methods require the introduction of heavy atoms, heteroatoms, or derivatization of light-emitting groups to achieve color modulation, which is not only cumbersome in synthesis but also easily sacrifices key properties such as phosphorescence lifetime, making it difficult to achieve a balance of multiple properties; multi-component doping modulation methods require the construction of ternary or even quaternary doped systems, which have extremely strict requirements on the energy level matching degree and doping ratio of each component, and multi-component mixing is prone to phase separation, resulting in uneven light emission color and poor modulation stability; energy transfer modulation methods have extremely high requirements on the distance between donor and acceptor, and can only be achieved in specific material states such as gel state, which cannot be adapted to conventional melting and solution preparation processes, and have serious lack of versatility; special schemes such as isomer engineering rely on specific molecular skeleton structures, have a narrow range of applications, and are difficult to achieve stable color modulation over a wide range from green to red.

[0006] At a deeper level, existing color modulation strategies still suffer from three major bottlenecks: First, insufficient understanding of the mechanisms, with a lack of systematic and in-depth understanding of the structure-activity relationship between molecular structure, stacking mode, and emission color, making it difficult to achieve rational material design; second, poor universality, with most strategies only applicable to specific molecular frameworks or material systems and unable to be extended to various p-RTP materials; and third, weak controllability, with the color modulation process easily affected by experimental conditions such as temperature and solvents, making it difficult to achieve precise and stable emission color control. These problems are intertwined and together constitute the main obstacles to the realization of multicolor and intelligent applications of organic p-RTP materials.

[0007] Patent CN117844476A discloses an organic room-temperature phosphorescent material with an ultra-long phosphorescence lifetime and its preparation method. This invention uses a polycyclic aromatic compound or its derivatives that do not contain heavy atoms or heteroatoms as the guest material and a rigid polymer as the host material, resulting in an organic room-temperature phosphorescent material with ultra-large Stokes shift and ultra-long phosphorescence lifetime. However, this patent achieves the change of phosphorescence color by altering the conjugation degree of the guest molecules, but still relies on ultraviolet light excitation.

[0008] In summary, the combined drawbacks of UV excitation dependence and single emission color make p-RTP materials unable to meet the basic requirements of safety and convenience in civilian applications, and also difficult to adapt to the performance requirements of multi-color and intelligent applications in high-end applications. Summary of the Invention

[0009] The purpose of this invention is to overcome the defects of the prior art and provide an organic light-emitting material with visible light excitation and tunable room temperature phosphorescence properties, as well as a method for preparing the same.

[0010] The objective of this invention can be achieved through the following technical solutions: An organic light-emitting material with visible light excitation and tunable room temperature phosphorescence properties includes a host material and a dopant. The host material is anthraquinone or its derivatives, and the dopant is a polycyclic aromatic compound or its derivative that does not contain heavy atoms or heteroatoms.

[0011] Furthermore, the polycyclic aromatic compound or its derivatives that do not contain heavy atoms and heteroatoms are selected from any of the following: .

[0012] Furthermore, the polycyclic aromatic compounds or their derivatives that do not contain heavy atoms and heteroatoms are selected from any of the following: .

[0013] Furthermore, the anthraquinones and their derivatives are selected from one or more of anthraquinone (AQ), 2-methyl-9,10-anthraquinone (MeAQ), 2-ethyl-9,10-anthraquinone (EtAQ), 2-propyl-9,10-anthraquinone (PrAQ), and 2-butyl-9,10-anthraquinone (BuAQ). The anthraquinones and their derivatives can achieve phosphorescence regulation.

[0014] Furthermore, the molar ratio of the doped guest to the host material is 1:10000 to 1:5.

[0015] Furthermore, the molar ratio of the dopant to the host material is 1:1000 to 1:10; preferably, the molar ratio of the dopant to the host material is 1:1000 to 1:100.

[0016] The present invention also provides a method for preparing an organic light-emitting material having visible light excitation and tunable room temperature phosphorescence properties as described in any of the preceding claims, the method comprising a solution evaporation method or a melt cooling method.

[0017] Furthermore, the solution evaporation method includes the following steps: dissolving the dopant and the host material in an organic solvent, and then removing the organic solvent by rotary evaporation to obtain an organic light-emitting material with visible light excitation and tunable room temperature phosphorescence properties.

[0018] The type and amount of the organic solvent are reasonably selected and determined based on the solubility of the dopant and the host material, and the specific operation can be carried out in accordance with the conventional solution evaporation process in this field.

[0019] Furthermore, the melt-cooling method includes the following steps: mixing the dopant and the host material, heating and melting them to obtain a uniform molten liquid; then cooling the molten liquid to obtain an organic light-emitting material with visible light excitation and tunable room temperature phosphorescence properties.

[0020] The heating temperature can be based on the melting point of the main material. For example, when 2-methyl-9,10-anthraquinone is used as the main material, the heating temperature is selected as 170°C and heated until the solid is completely melted. The specific operation can be performed in accordance with the conventional melting process in this field.

[0021] The present invention also provides an application of an organic light-emitting material having visible light excitation and tunable room temperature phosphorescence properties as described in any of the preceding claims in information storage, anti-counterfeiting coatings, data encryption and anti-counterfeiting, special printing technology, programmable labels or bioimaging.

[0022] Compared with the prior art, the present invention has the following beneficial effects: (1) In view of the shortcomings of existing organic room temperature phosphorescent materials that rely on ultraviolet light excitation and have a single emission color, this invention uses polycyclic aromatic compounds or their derivatives that do not contain heavy atoms and heteroatoms as dopants and anthraquinone compounds and their derivatives as main materials, and performs doping and composite by solution volatilization or melt cooling method to obtain organic light luminescent materials with visible light excitation and tunable room temperature phosphorescence characteristics.

[0023] This invention constructs a novel high-brightness host-guest doped organic room-temperature phosphorescent material excited by visible light, based on the intermolecular charge transfer mechanism. The intermolecular charge transfer strategy endows the material with several superior properties: First, the energy levels of the charge-transferred excited state correspond to the transition from the highest occupied molecular orbital of the donor molecule to the lowest unoccupied molecular orbital of the acceptor molecule, resulting in a smaller band gap and thus achieving a significant redshift of the excitation wavelength from the ultraviolet to the visible light region; second, the charge-transferred state can serve as an intermediate state, effectively promoting intersystem crossover processes; third, the activation of the host dark triplet state significantly improves exciton utilization, thereby greatly enhancing the material's luminescence efficiency. Based on these synergistic effects, this invention successfully prepares an organic light-emitting material capable of highly efficient phosphorescence emission under visible light excitation, breaking through the dependence of traditional organic room-temperature phosphorescent materials on ultraviolet light excitation.

[0024] This invention precisely regulates the energy transfer efficiency between the host and guest molecules by controlling the alkyl chain length of the host material, achieving continuous control over the phosphorescence color from green to red. Under visible light excitation, the host-guest complex is excited to a charge-transfer state and rapidly separates into stable free radical ion pairs. Subsequent charge recombination generates triplet excitons on both the host and guest molecules. The energy transfer intermediate plays a dual role: firstly, it stores excitation energy, promoting the formation of triplet excitons in the host; secondly, it promotes spin-orbit coupling of the guest molecules, thus achieving synergistic phosphorescence emission from both components. As the length of the host alkyl chain increases, the enhanced steric hindrance and increased intramolecular charge transfer inhibit the formation of the energy transfer intermediate and weaken the corresponding visible light absorption, while simultaneously lowering the energy level of the charge-transfer state. At this point, the charge recombination process preferentially generates low-energy guest triplet states, ultimately causing the afterglow color of the material to change from host-dominated green to guest-dominated red. This invention solves the technical problem of the single emission color in existing organic room-temperature phosphorescent materials.

[0025] (2) The host and guest materials used in this invention are widely available, inexpensive and biocompatible. The preparation process is simple and convenient, easy to operate and short in time. It does not require expensive instruments and is easy to scale up. The prepared organic light-emitting materials have excellent light-emitting performance, and have the characteristics of high transparency, color diversity and bendability and stretchability, which are suitable for the use needs of various application scenarios.

[0026] (3) The organic light-emitting materials prepared by this invention, which have visible light excitation and adjustable room temperature phosphorescence properties, have a wide range of applications and irreplaceable advantages in fields such as information storage, data encryption and anti-counterfeiting, special printing technology, and bioimaging. The market application prospects are very broad. Attached Figure Description

[0027] Figure 1 The fluorescence emission spectrum and phosphorescence emission spectrum of the organic light-emitting material Py-AQ in Example 1 of the present invention are shown, wherein the excitation wavelength of the ultraviolet light source is 365 nm. Figure 2 The fluorescence emission spectrum and phosphorescence emission spectrum of the organic light-emitting material Py-MeAQ in Example 2 of the present invention are shown, wherein the excitation wavelength of the ultraviolet light source is 365 nm. Figure 3 The fluorescence emission spectrum and phosphorescence emission spectrum of the organic light-emitting material Py-EtAQ in Example 3 of the present invention are shown, wherein the excitation wavelength of the ultraviolet light source is 365 nm. Figure 4 The fluorescence emission spectrum and phosphorescence emission spectrum of the organic light-emitting material Py-PrAQ in Example 4 of the present invention are shown, wherein the excitation wavelength of the ultraviolet light source is 365 nm. Figure 5The fluorescence emission spectrum and phosphorescence emission spectrum of the organic light-emitting material Py-BuAQ in Example 5 of the present invention are shown, wherein the excitation wavelength of the ultraviolet light source is 365 nm. Figure 6 The images show the phosphorescence effect of the organic light-emitting materials in Examples 1-5 of this invention under an ultraviolet light source, wherein the excitation wavelength of the ultraviolet light source is 365 nm. Figure 7 The images show the phosphorescence effect of the organic light-emitting materials in Examples 1-5 of this invention under sunlight and white LED light sources. Figure 8 The images show the phosphorescence effect of the organic light-emitting materials in Examples 6 and 7 of this invention under sunlight, white LED light source and ultraviolet light source, wherein the excitation wavelength of the ultraviolet light source is 365 nm. Figure 9 This is a diagram illustrating the application effect of the organic light-emitting material of Embodiment 1 of the present invention in a traffic warning sign; Figure 10 The diagram shows the application effect of the organic light-emitting material in the bioimaging probe according to Example 1 of the present invention. (a) is a bioimaging application diagram of the material under white light source and ultraviolet light source, and (b) is a signal-to-noise ratio (SBR) comparison diagram of the material under white light source and ultraviolet light source. The excitation wavelength of the ultraviolet light source is 365 nm. Detailed Implementation

[0028] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0029] Unless otherwise specified, all raw materials used in this invention are commercially available products, such as those described in the following embodiments: Phthalic anhydride (98% purity) and pyrene (98% purity) were purchased from Beijing Bailingwei Technology Co., Ltd. Anthraquinone (98% purity), toluene (99% purity), ethylbenzene (98% purity), n-propylbenzene (99% purity), and n-butylbenzene (98% purity) were all purchased from Shanghai Maclean Biochemical Technology Co., Ltd. The amphiphilic block copolymer PEG-b-PPG-b-PEG was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. Anhydrous aluminum chloride (99% purity), concentrated hydrochloric acid, chloroform, and concentrated sulfuric acid were purchased from Shanghai Titan Technology Co., Ltd.

[0030] The preparation methods of 2-methyl-9,10-anthraquinone, 2-ethyl-9,10-anthraquinone, 2-propyl-9,10-anthraquinone and 2-butyl-9,10-anthraquinone used in the embodiments of the present invention are as follows: (1) Synthesis of 2-methyl-9,10-anthraquinone ; S1. Phthalic anhydride (30 mmol), anhydrous aluminum chloride (72 mmol), and chloroform (50 mL) were added sequentially to a 100 mL round-bottom flask, and the mixture was stirred until homogeneous. Then, toluene (30 mmol) was slowly added dropwise under stirring. After the addition was complete, the reaction mixture was heated to 50 °C and reacted at this temperature for 2 h. After the reaction was completed, the system was cooled to room temperature, and a mixture of concentrated hydrochloric acid (20 mL) and crushed ice (40 g) was slowly added to quench the reaction. After separation, the organic phase was collected, and the aqueous phase was extracted with chloroform (3 × 50 mL). All organic phases were combined, dried over anhydrous sodium sulfate, and the solvent was removed by vacuum distillation to obtain a crude intermediate. This intermediate did not require further purification and was used directly in the next reaction.

[0031] S2. Transfer the crude intermediate obtained in step S1 to a pressure-resistant reaction flask, add concentrated sulfuric acid (50 mL), seal the flask, and heat to 110 °C. React at this temperature for 1 h. After the reaction is complete, slowly pour the reaction solution into excess ice water, stir until homogeneous, and extract with ethyl acetate. Combine the organic layers and dry with anhydrous sodium sulfate. The crude product is then purified by silica gel column chromatography to obtain a light yellow solid. After further purification by recrystallization, high-purity 2-methyl-9,10-anthraquinone is finally obtained.

[0032] (2) Synthesis of 2-ethyl-9,10-anthraquinone Following the above method for synthesizing 2-methyl-9,10-anthraquinone (steps S1-S2), only the toluene (30 mmol) in step S1 was replaced with an equal amount of ethylbenzene (30 mmol), while keeping the other reaction conditions the same, and high-purity 2-ethyl-9,10-anthraquinone was finally obtained.

[0033] (3) Synthesis of 2-propyl-9,10-anthraquinone Following the above method for synthesizing 2-methyl-9,10-anthraquinone (steps S1-S2), only the toluene (30 mmol) in step S1 was replaced with an equal amount of n-propylbenzene (30 mmol), while keeping the other reaction conditions the same, and high-purity 2-propyl-9,10-anthraquinone was finally obtained.

[0034] (4) Synthesis of 2-butyl-9,10-anthraquinone Following the above method for synthesizing 2-methyl-9,10-anthraquinone (steps S1-S2), only the toluene (30 mmol) in step S1 was replaced with an equal amount of n-butylbenzene (30 mmol), while keeping the other reaction conditions the same, and high-purity 2-butyl-9,10-anthraquinone was finally obtained.

[0035] Example 1 An organic light-emitting material with visible light excitation and green room temperature phosphorescence properties is prepared by the following method: The dopant is pyrene, and its structural formula is shown in Equation 1 below: ; The main material is anthraquinone, and its structural formula is shown in Formula 2 below: ; Weigh the corresponding mass of sample according to the molar ratio of guest pyrene to host anthraquinone of 1:100, place both in a round-bottom flask, add dichloromethane to completely dissolve the solid; then remove the dichloromethane by rotary evaporation, and place the obtained solid in a vacuum oven at 30°C overnight to dry, thus obtaining an organic light-emitting material with visible light excitation and green room temperature phosphorescence properties (named Py-AQ).

[0036] Figure 1 The fluorescence emission spectrum and phosphorescence emission spectrum of the organic light-emitting material obtained in this embodiment were measured with an excitation wavelength of 365 nm; the phosphorescence effect of the organic light-emitting material under ultraviolet light is as follows. Figure 6 As shown; the phosphorescence effect of this organic light-emitting material under LED light source illumination is as follows. Figure 7 As shown.

[0037] Example 2 An organic luminescent material exhibiting visible light excitation and pale yellow room-temperature phosphorescence properties is prepared as follows: The dopant is pyrene; The main material is 2-methyl-9,10-anthraquinone, and its structural formula is shown in Formula 3 below: ; Weigh the corresponding mass of sample according to the molar ratio of guest pyrene to host 2-methyl-9,10-anthraquinone of 1:100, and place them in a high-temperature resistant reaction vessel and mix them evenly. Then heat the system to 170°C and keep it at a constant temperature until the raw materials are completely melted. Continue stirring to ensure that the host and guest are fully mixed in the molten state. After stirring is completed, stop heating and let the system cool naturally to room temperature to obtain an organic light-emitting material (Py-MeAQ) with visible light excitation and light yellow room temperature phosphorescence properties.

[0038] Figure 2 The fluorescence and phosphorescence emission spectra of the organic light-emitting material obtained in this embodiment are shown, with an excitation wavelength of 365 nm. The phosphorescence effect of this organic light-emitting material under ultraviolet light is as follows: Figure 6 As shown; the phosphorescence effect of this organic light-emitting material under LED light source illumination is as follows. Figure 7 As shown.

[0039] Example 3 An organic light-emitting material exhibiting visible light excitation and yellow room-temperature phosphorescence properties is prepared as follows: The dopant is pyrene; The main material is 2-ethyl-9,10-anthraquinone, and its structural formula is shown in Formula 4 below: ; Weigh the corresponding mass of sample according to the molar ratio of guest pyrene to host 2-ethyl-9,10-anthraquinone of 1:100, and place them in a high-temperature resistant reaction vessel and mix them evenly. Then heat the system to 170°C and keep it at a constant temperature until the raw materials are completely melted. Continue stirring to ensure that the host and guest are fully mixed in the molten state. After stirring is completed, stop heating and let the system cool naturally to room temperature to obtain an organic light-emitting material (Py-EtAQ) with visible light excitation and yellow room temperature phosphorescence properties. Figure 3 The fluorescence and phosphorescence emission spectra of the organic light-emitting material obtained in this embodiment are shown, with an excitation wavelength of 365 nm; the phosphorescence effect of the organic light-emitting material under ultraviolet light is as follows. Figure 6 As shown; the phosphorescence effect of this organic light-emitting material under LED light source illumination is as follows. Figure 7 As shown.

[0040] Example 4 An organic light-emitting material exhibiting visible light excitation and orange room-temperature phosphorescence properties is prepared as follows: The dopant is pyrene; The main material is 2-propyl-9,10-anthraquinone, and its structural formula is shown in Formula 5 below: ; Weigh the corresponding mass of sample according to the molar ratio of guest pyrene to host 2-propyl-9,10-anthraquinone of 1:100, and place them in a high-temperature resistant reaction vessel and mix them evenly. Then heat the system to 170°C and keep it at a constant temperature until the raw materials are completely melted. Continue stirring to ensure that the host and guest are fully mixed in the molten state. After stirring is completed, stop heating and let the system cool naturally to room temperature to obtain an organic light-emitting material (Py-PrAQ) with visible light excitation and orange room temperature phosphorescence properties. Figure 4 The fluorescence and phosphorescence emission spectra of the organic light-emitting material obtained in this embodiment are shown, with an excitation wavelength of 365 nm; the phosphorescence effect of the organic light-emitting material under ultraviolet light is as follows. Figure 6 As shown; the phosphorescence effect of this organic light-emitting material under LED light source illumination is as follows. Figure 7 As shown.

[0041] Example 5 An organic light-emitting material exhibiting visible light excitation and red room-temperature phosphorescence properties is prepared as follows: The dopant is pyrene; The main material is 2-butyl-9,10-anthraquinone, and its structure is shown in Formula 6 below: ; Weigh the corresponding mass of sample according to the molar ratio of guest pyrene to host 2-butyl-9,10-anthraquinone of 1:100, and place them in a high-temperature resistant reaction vessel and mix them evenly. Then heat the system to 170°C and keep it at a constant temperature until the raw materials are completely melted. Continue stirring to ensure that the host and guest are fully mixed in the molten state. After stirring is completed, stop heating and let the system cool naturally to room temperature to obtain an organic light-emitting material (Py-BuAQ) with visible light excitation and red room temperature phosphorescence properties. Figure 5 The fluorescence and phosphorescence emission spectra of the organic light-emitting material obtained in this embodiment are shown, with an excitation wavelength of 365 nm; the phosphorescence effect of the organic light-emitting material under ultraviolet light is as follows. Figure 6 As shown; the phosphorescence effect of this organic light-emitting material under LED light source illumination is as follows. Figure 7 As shown.

[0042] like Figure 7 As shown, the room-temperature phosphorescent materials prepared in Examples 1 to 5 all exhibit excellent visible light excitation capabilities, with afterglow durations reaching up to 5 seconds. Figure 6 As shown, with the increase in alkyl chain length in the main molecule, the room-temperature phosphorescent materials prepared in Examples 1 to 5 exhibit phosphorescence emission colors of green, light yellow, yellow, orange, and red under a 365 nm UV lamp, respectively, achieving effective control over a wide range of phosphorescence colors. Further combined with... Figures 1 to 5 Delayed emission spectroscopy analysis revealed that the materials prepared in Examples 1 to 5 mainly exhibited three characteristic emission peaks at 550 nm, 600 nm, and 660 nm. Among these, the relative intensity of the emission peak at 550 nm gradually decreased with increasing alkyl chain length. Figure 1 The main peak of the medium-delayed emission spectrum is located at 550 nm, which corresponds perfectly to the phenomenon of green phosphorescence emitted by the material in Example 1; while at... Figure 5 The main peaks of the medium-delayed emission spectrum shifted to 600 nm and 660 nm, matching the red phosphorescence emission characteristics of the material in Example 5.

[0043] Example 6 An organic light-emitting material exhibiting visible light excitation and orange room-temperature phosphorescence properties is prepared as follows: The dopant guest is benzo[a]perylene, and its structural formula is shown in Equation 7 below: ; The main material is anthraquinone; Weigh the corresponding mass of sample according to the molar ratio of guest benzo[a]perylene to host anthraquinone of 1:100, place both in a round-bottom flask, add dichloromethane to completely dissolve the solid; then remove the dichloromethane by rotary evaporation, and place the obtained solid in a vacuum oven at 30°C overnight to dry, thus obtaining an organic light-emitting material (BePe-AQ) with visible light excitation and orange room temperature phosphorescence properties.

[0044] The phosphorescence effect of this organic light-emitting material under different light sources is as follows: Figure 8 As shown: Under 365 nm ultraviolet light irradiation, the material emits orange phosphorescence, and after the ultraviolet light is turned off, it exhibits an orange phosphorescence afterglow for 3 seconds; under sunlight irradiation, the material appears yellow, and after LED light source irradiation and then the light source is turned off, a red phosphorescence afterglow for 2 seconds can be observed.

[0045] Example 7 An organic light-emitting material exhibiting visible light excitation and orange room-temperature phosphorescence properties is prepared as follows: The dopant is benzanthracene, and its structural formula is shown in Formula 8 below: ; The main material is anthraquinone; Samples of the same mass with a guest benzanthracene to anthraquinone molar ratio of 1:100 were placed in a round-bottom flask, and dichloromethane was added to completely dissolve the solid. The dichloromethane was then removed by rotary evaporation, and the resulting solid was dried overnight in a vacuum oven at 30°C to obtain an organic light-emitting material (BeAn-AQ) with visible light excitation and orange room temperature phosphorescence properties.

[0046] The phosphorescence effect of this organic light-emitting material under different light sources is as follows: Figure 8 As shown: Under 365 nm ultraviolet light, the material emits yellow phosphorescence, and after the ultraviolet light is turned off, it exhibits an orange phosphorescence afterglow for 2 seconds; under sunlight, the material appears yellow, and after being illuminated by an LED light source and then the light source is turned off, a red phosphorescence afterglow for 2 seconds can be observed.

[0047] Example 8 Application of the organic light-emitting material of this invention in traffic warning signs The organic luminescent material prepared by this invention, which possesses visible light excitation and room temperature phosphorescence properties, can be used in the production of traffic warning signs. Its specific applications and effects are as follows: like Figure 9 As shown, the traffic indicator prepared using the Py-AQ powder prepared in Example 1 of this invention exhibits a bright afterglow lasting for several seconds after being excited by a 365 nm ultraviolet light source and a white LED flashlight source. This afterglow characteristic can effectively utilize the headlight source of automobiles to provide pedestrians with immediate visual warnings, demonstrating the practical application potential of the material of this invention in the field of traffic positioning and signage.

[0048] Example 9 Application of organic light-emitting materials in bioimaging probes The organic light-emitting material prepared by this invention, which possesses visible light excitation and room-temperature phosphorescence properties, can be used as a high-performance bioimaging probe. Specific applications and effects are as follows: Py-AQ, a green organic luminescent material with visible light excitation and room temperature phosphorescence properties prepared in Example 1, was selected as the luminescent core. PEG-b-PPG-b-PEG (trade name F127), an amphiphilic block copolymer with excellent biocompatibility, was chosen as the coating agent. A top-down method was used to prepare an aqueous dispersion of Py-AQ@F127 nanoparticles. The specific operation was as follows: Py-AQ powder and F127 were dispersed in deionized water at a mass ratio of 1:20. The mixture was ultrasonically treated for 30 min to ensure thorough dispersion, and then filtered through a 0.22 μm filter membrane to remove large particle impurities. The nanoparticles were characterized by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The results showed that the obtained Py-AQ@F127 nanoparticles had a particle size distribution of approximately 50 nm.

[0049] Healthy Balb / c mice were used as the experimental model, and 50 μL of a solution containing 1 mg·mL⁻¹ was prepared. -1 The Py-AQ@F127 nanoparticle aqueous dispersion was injected subcutaneously into the subcutaneous tissue of mice. The injection site was pre-irradiated with white light (50 W, irradiation distance 10 cm) and 365 nm ultraviolet light (30 W, irradiation distance 10 cm) for 30 s each. The mice were then placed in an in vivo imaging system (IVIS Spectrum, test mode: bioluminescence mode, exposure time 10 s, detection wavelength range 500~600 nm) for imaging tests. Figure 10 This image illustrates the application of this material in bioimaging. Figure 10 Image a shows a photograph of the in vivo image. The imaging results show that a strong afterglow signal from the injection site in the mouse was clearly observed under both excitation methods, with no significant signal attenuation. Quantitative analysis of the imaging data was performed, and the signal-to-background ratio (SBR) was calculated. The results are as follows: Figure 10As shown in b, the SBR value reaches 1093 under white light excitation and 696 under 365nm ultraviolet light excitation. This result indicates that the organic luminescent material of this invention exhibits significantly better bioimaging performance under visible light excitation than under ultraviolet light excitation, possessing higher detection sensitivity and signal recognition. According to a review of existing literature, the SBR value of the Py-AQ@F127 nanoprobe in this embodiment is among the highest reported levels for organic p-RTP nanoimaging probes. Simultaneously, the visible light excitation mode avoids the high toxicity and low tissue penetration defects of ultraviolet light, resulting in higher biosafety and deeper imaging depth in in vivo applications.

[0050] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An organic light-emitting material with visible light excitation and tunable room-temperature phosphorescence properties, characterized in that, It includes a host material and a dopant, wherein the host material is anthraquinone and its derivatives, and the dopant is a polycyclic aromatic compound or its derivative that does not contain heavy atoms and heteroatoms.

2. The organic light-emitting material with visible light excitation and tunable room-temperature phosphorescence properties according to claim 1, characterized in that, The polycyclic aromatic compounds or their derivatives that do not contain heavy atoms and heteroatoms are selected from any one of the following: 。 3. The organic light-emitting material with visible light excitation and tunable room-temperature phosphorescence properties according to claim 2, characterized in that, Polycyclic aromatic compounds or their derivatives that do not contain heavy atoms and heteroatoms are selected from any of the following: 。 4. The organic light-emitting material with visible light excitation and tunable room-temperature phosphorescence properties according to claim 1, characterized in that, The anthraquinones and their derivatives are selected from one or more of anthraquinones, 2-methyl-9,10-anthraquinones, 2-ethyl-9,10-anthraquinones, 2-propyl-9,10-anthraquinones, and 2-butyl-9,10-anthraquinones.

5. The organic light-emitting material with visible light excitation and tunable room-temperature phosphorescence properties according to claim 1, characterized in that, The molar ratio of the doped guest to the host material is from 1:10000 to 1:

5.

6. The organic light-emitting material with visible light excitation and tunable room-temperature phosphorescence properties according to claim 5, characterized in that, The molar ratio of the doped guest to the host material is 1:1000 to 1:

10.

7. A method for preparing an organic light-emitting material with visible light excitation and tunable room-temperature phosphorescence properties as described in any one of claims 1 to 6, characterized in that, The preparation methods include solution evaporation or melt cooling.

8. The method for preparing the organic light-emitting material with visible light excitation and tunable room temperature phosphorescence properties according to claim 7, characterized in that, The solution evaporation method includes the following steps: dissolving the dopant and the host material in an organic solvent, and then removing the organic solvent to obtain an organic light-emitting material with visible light excitation and tunable room temperature phosphorescence properties.

9. The method for preparing the organic light-emitting material with visible light excitation and tunable room temperature phosphorescence properties according to claim 7, characterized in that, The melt-cooling method includes the following steps: mixing the dopant and the host material, heating and melting them to obtain a uniform molten liquid; then cooling the molten liquid to obtain an organic light-emitting material with visible light excitation and tunable room temperature phosphorescence properties.

10. The application of an organic light-emitting material with visible light excitation and tunable room temperature phosphorescence properties as described in any one of claims 1 to 6 in information storage, anti-counterfeiting coatings, data encryption and anti-counterfeiting, special printing technology, programmable labels or bioimaging.

Images