A host-guest doped room temperature phosphorescent flexible crystal and preparation method thereof

Abstract

The invention discloses a host-guest doped room temperature phosphorescent flexible crystal and a preparation method thereof. The invention selects triphenylene as a host molecule of the material, pyrene as a guest molecule, dopes a small amount of pyrene into the triphenylene, adds an organic solvent, and prepares a novel room temperature phosphorescent material through a one-step mixing, and then cultivates the flexible crystal through a solvent diffusion method. The characteristics of the material are that the material is bendable in a crystal state and the material cannot produce room temperature phosphorescence after being irradiated with natural light; however, after being irradiated with ultraviolet light with a wavelength of 365nm, the material can produce room temperature phosphorescence with an emission wavelength of 600nm. The host-guest doped room temperature phosphorescent material obtained by the invention has broad application prospects in the field of flexible devices or wearable devices.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic photoelectric functional materials, and specifically relates to a host-guest system room temperature phosphorescent material and a preparation method thereof, wherein the guest is uniformly doped into the host. The material has the advantages of simple manufacturing process, low raw material cost, environmentally friendly and non-toxic materials, and good phosphorescent performance. Background Art

[0002] Within a certain period of time (>10 -8 s) Substances that can produce cold luminescence are called phosphorescent materials. Compared with fluorescent materials, they have a longer decay life, so they have important application value in the fields of anti-counterfeiting, information encryption, bio-imaging and wearable devices. Existing room temperature phosphorescent materials are mainly divided into two categories: metal-containing room temperature phosphorescent materials and pure organic room temperature phosphorescent materials. Pure organic room temperature phosphorescent materials do not contain heavy metals and phosphorescence can be observed at room temperature. Compared with metal-containing phosphorescent materials, they are cheaper, relatively safe and non-toxic, and are currently a hot topic of research.

[0003] However, due to the weak spin-orbit coupling and fast non-radiative decay of triplet excitons caused by thermal molecular motion and collision, as well as the quenching effect of surrounding oxygen and moisture, pure organic phosphorescent materials with good performance are very scarce, which greatly limits their practical applications. Therefore, it is of great significance to develop pure organic room temperature phosphorescent flexible materials with good performance. Summary of the invention

[0004] The present invention provides a host-guest doped room temperature phosphorescent flexible crystal material and a preparation method thereof. The present invention is to add a uniform mixed solution of triphenylene, pyrene and dichloromethane into a rotating bottle, remove the solvent by rotary evaporation, and then prepare a room temperature phosphorescent flexible crystal with excellent performance by a solvent diffusion method.

[0005] The characteristics of the material are that the material is bendable in the crystal state and does not produce room temperature phosphorescence after being irradiated by natural light; however, after being irradiated by ultraviolet light with a wavelength of 365nm, the material can produce room temperature phosphorescence with an emission wavelength of 600nm. The host-guest doped room temperature phosphorescent material obtained by the present invention has broad application prospects in the field of flexible devices or wearable devices.

[0006] The technical solution of the present invention is as follows:

[0007] A method for preparing a host-guest doped room temperature phosphorescent flexible crystal comprises the following steps:

[0008] (1) mixing a host compound, a guest compound and an organic solvent, mixing them uniformly by ultrasonication, and then removing the solvent by rotary evaporation to obtain a host-guest doped room temperature phosphorescent material (white powder);

[0009] The molar ratio of the host compound to the guest compound is 1:0.001-0.01;

[0010] The volume molar ratio of the organic solvent to the main compound is 20-30:1 mL / mmol; the organic solvent is dichloromethane;

[0011] The host compound is triphenylene, and the guest compound is pyrene, and the structural formulas are as follows:

[0012]

[0013] The temperature of the rotary evaporation is 45-55°C and the rotation speed is 30-60rpm;

[0014] (2) dissolving the host-guest doped room temperature phosphorescent material obtained in step (1) in a good solvent, then adding a poor solvent, and allowing the resulting mixture to evaporate naturally at room temperature to dryness, thereby obtaining a host-guest doped room temperature phosphorescent flexible crystal;

[0015] The mass volume ratio of the host-guest doped room temperature phosphorescent material to the good solvent is 15-30:1 mg / mL; the good solvent is dichloromethane;

[0016] The mass volume ratio of the host-guest doped room temperature phosphorescent material to the poor solvent is 10-20:1 mg / mL; and the poor solvent is methanol.

[0017] The present invention also relates to a host-guest doped room temperature phosphorescent flexible crystal prepared by the preparation method.

[0018] The host-guest doped room temperature phosphorescent flexible crystals of the present invention can be applied to the fields of flexible devices and wearable devices.

[0019] The beneficial effects of the present invention are:

[0020] First, the preparation method is simple, and room temperature phosphorescent materials can be obtained through one-step mixing, which provides conditions for mass production;

[0021] Second, the raw materials used in this method are environmentally friendly, non-toxic, and inexpensive, which meets the requirements of green production and is expected to be applied in real life;

[0022] Third, the room-temperature phosphorescent flexible crystals prepared by this preparation method have good bending properties and luminescence properties, and can possess room-temperature phosphorescent luminescence properties when bent 180 degrees.

[0023] In summary, the material provided by the present invention has a simple manufacturing process, low raw material cost, environmentally friendly and non-toxic materials, and good phosphorescence performance, and has broad application value in the fields of flexible devices and wearable devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 : Natural light, fluorescence and phosphorescence photographs of a single crystal of the host-guest room temperature phosphorescent material prepared in Example 1 in a bent state.

[0025] Figure 2 : Among them, a, b, c are natural light, fluorescence and phosphorescence photos of the guest raw material pyrene, respectively, with no phosphorescence emission; d, e, f are natural light, fluorescence and phosphorescence photos of the host raw material triphenylene, respectively, with no phosphorescence emission; g, h, i are natural light, fluorescence and phosphorescence luminescence photos of the host-guest room temperature phosphorescent material prepared in Example 1, respectively, with red phosphorescence emission.

[0026] Figure 3 : The fluorescence optimal emission spectra of the main raw material triphenylene and the guest raw material pyrene in Example 1.

[0027] Figure 4 : Time-resolved phosphorescence spectrum of the host-guest room temperature phosphorescent material prepared in Example 1.

[0028] Figure 5 : Phosphorescence lifetime decay curve of the host-guest room temperature phosphorescent material prepared in Example 1. DETAILED DESCRIPTION

[0029] The present invention is further described below by means of specific embodiments, but the protection scope of the present invention is not limited thereto.

[0030] Example 1: The molar ratio of triphenylene to pyrene is 1000:1

[0031] (1) Preparation

[0032] In a 50mL rotating bottle of a rotary evaporator, add 0.2283g of triphenylene, 0.0002g of pyrene and 25mL of dichloromethane in sequence, wherein the molar amounts of triphenylene and pyrene are 1mmol and 0.001mmol, respectively. Ultrasonicate the rotating bottle for 10 minutes to mix the internal solution evenly. Fix the ultrasonic rotating bottle on the rotating sealing shaft of the rotary evaporator, and adjust the appropriate position and speed to 50rpm, and allow the rotating bottle to evaporate the solvent in a 50°C water bath. After the solvent is completely evaporated, take out the rotating bottle, cool it to room temperature, and obtain a white powder. Transfer 0.2285g of white powder to a crystal culture bottle, add 8mL of dichloromethane solvent to completely dissolve it, and then add 12mL of methanol solvent. Slowly evaporate the solvent at room temperature, and after 10 days, flexible crystals with room temperature phosphorescence properties are obtained, such as Figure 1 It shows purple fluorescence under ultraviolet light, and red room temperature phosphorescence when the ultraviolet light is turned off. Figure 2 shown.

[0033] (2) Basic optical characterization

[0034] The prepared room temperature phosphorescent material and its raw material fluorescence optimal emission spectrum, such as Figure 3 As shown. The best emission wavelength of triphenylene is 385nm, and the fluorescence is purple light; the best emission wavelength of pyrene is 460nm, and the fluorescence is blue light. Through time-resolved phosphorescence spectroscopy, as shown Figure 4 As shown, its phosphorescence emission peak is at 600nm, and the phosphorescence is red. Figure 5 As shown, the phosphorescence lifetime of the material was characterized and its lifetime was found to be 406ms. Through the above optical characterization, it can be seen that the material emits violet light for fluorescence and red light for phosphorescence, which is consistent with the results seen by the naked eye.

[0035] Example 2: The molar ratio of triphenylene to pyrene is 100:1

[0036] (1) Preparation

[0037] In a 50mL rotating bottle of a rotary evaporator, 0.2283g of triphenylene, 0.0020g of pyrene and 25mL of dichloromethane were added in sequence, wherein the molar amounts of triphenylene and pyrene were 1mmol and 0.01mmol, respectively. Ultrasonicate the rotating bottle for 10 minutes to mix the internal solution evenly. Fix the ultrasonic rotating bottle on the rotating seal shaft of the rotary evaporator, and adjust the appropriate position and speed to 50rpm, and let the rotating bottle evaporate the solvent in a water bath at 50°C. After the solvent is completely evaporated, take out the rotating bottle and cool it to room temperature to obtain a white powder. Transfer 0.2303g of white powder to a crystal culture bottle, add 9mL of dichloromethane solvent to completely dissolve it, and then add 12mL of methanol solvent. Slowly evaporate the solvent, and flexible crystals with room temperature phosphorescence properties are obtained after 10 days.

[0038] (2) The basic optical characteristics are the same as those in Example 1.

[0039] The above description shows and describes several preferred embodiments of the invention, but as mentioned above, it should be understood that the invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the invention concept described herein through the above teachings or the technology or knowledge of the relevant field. Changes and modifications made by those skilled in the art should be within the scope of protection of the claims attached to the invention without departing from the spirit and scope of the invention.

Claims

1. A method for preparing a host-guest doped room temperature phosphorescent flexible crystal, characterized in that: The steps include: (1) mixing a host compound, a guest compound and an organic solvent, mixing them uniformly by ultrasonication, and then removing the solvent by rotary evaporation to obtain a host-guest doped room temperature phosphorescent material; The molar ratio of the host compound to the guest compound is 1:0.001-0.01; The organic solvent is dichloromethane; The host compound is triphenylene, and the guest compound is pyrene, and the structural formulas are as follows: (2) dissolving the host-guest doped room temperature phosphorescent material obtained in step (1) in a good solvent, then adding a poor solvent, and allowing the resulting mixture to evaporate naturally at room temperature to dryness, thereby obtaining a host-guest doped room temperature phosphorescent flexible crystal; The good solvent is dichloromethane; The poor solvent is methanol.

2. The method for preparing the host-guest doped room temperature phosphorescent flexible crystal according to claim 1, characterized in that: In step (1), the volume molar ratio of the organic solvent to the main compound is 20-30:1 mL / mmol.

3. The method for preparing the host-guest doped room temperature phosphorescent flexible crystal according to claim 1, characterized in that: In step (1), the temperature of the rotary evaporation is 45-55° C., and the rotation speed is 30-60 rpm.

4. The method for preparing the host-guest doped room temperature phosphorescent flexible crystal according to claim 1, characterized in that: In step (2), the mass volume ratio of the host-guest doped room temperature phosphorescent material to the good solvent is 15-30:1 mg / mL.

5. The method for preparing the host-guest doped room temperature phosphorescent flexible crystal according to claim 1, characterized in that: In step (2), the mass volume ratio of the host-guest doped room temperature phosphorescent material to the poor solvent is 10-20:1 mg / mL.

6. The host-guest doped room temperature phosphorescent flexible crystal obtained by the preparation method according to any one of claims 1 to 5.

7. Application of the host-guest doped room temperature phosphorescent flexible crystal as claimed in claim 6 in flexible devices.

8. Application of the host-guest doped room temperature phosphorescent flexible crystal as described in claim 6 in wearable devices.

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