A phenylpyridine salt derivative G, a room-temperature phosphorescent supramolecular gel and a preparation method and application thereof

Abstract

The application discloses a phenylpyridine salt derivative G, a room-temperature phosphorescent supramolecular gel and a preparation method and application thereof. The preparation method of the room-temperature phosphorescent supramolecular gel comprises the following steps: taking Cucurbit[8]uril (CB[8]) as a host, a phenylpyridine salt derivative containing a urea-based pyrimidone (UPy) quadruple hydrogen bond site as a guest, self-assembling a supramolecular assembly phosphorescent material in a 1:2 molar ratio in an aqueous solution; and introducing the assembly into a polyvinyl alcohol (PVA) matrix to obtain a humidity-responsive room-temperature phosphorescent supramolecular gel. The assembly and the supramolecular gel both present phosphorescent emission at room temperature. Under the dual constraints of macrocycle limitation and multiple hydrogen bonds on the phosphorescent molecules, the phosphorescent intensity and lifetime of the supramolecular gel are greatly enhanced compared with the assembly. Meanwhile, the phosphorescent intensity and the light-emitting color of the supramolecular gel change with the water content of the gel or the environmental humidity, realizing a visual response from green to blue, and the supramolecular gel can be applied to humidity sensing, anti-counterfeiting and information encryption.

Description

Technical Field

[0001] This invention belongs to the field of organic light-emitting materials technology, and particularly relates to a phenylpyridine salt derivative G, a room temperature phosphorescent supramolecular gel, its preparation method and application. Background Technology

[0002] Pure organic room-temperature phosphorescent (RTP) materials have wide applications in optoelectronics and sensing due to their unique excited-state triplet properties. However, the weak spin-orbit coupling (SOC) of organic molecules and the susceptibility of triplet excitons to thermal motion and environmental quenching make the construction of efficient and stable RTP systems extremely challenging. Currently, supramolecular assembly using macrocyclic host molecules (such as cucurbita) and the suppression of nonradiative transitions through restricted intramolecular motion (RIM) mechanisms are effective strategies for obtaining RTPs.

[0003] Patent CN120535763A provides a supramolecular system with near-infrared phosphorescence and thermally activated delayed fluorescence, using cucurbit[8]urea as the host material and phenylpyridine derivatives as the guest material. Patent CN118931528A provides a class of host-guest phosphorescent complexes. The macrocyclic host cucurbit[6]urea is complexed with benzoic acid and its derivatives, thereby improving its phosphorescence quantum yield and lifetime. Although the host-guest inclusion strategy based on cucurbiturea can induce phosphorescence emission, the existing technology still has defects: the traditional system mainly relies on the hydrophobic interaction or ion-dipole interaction between the host and guest for assembly. The binding strength of this non-covalent force on the luminescent guest is limited, and it is difficult to completely suppress the energy dissipation caused by low-frequency vibration, so the phosphorescence quantum yield is difficult to be further improved. In fact, based on host-guest assembly, the introduction of strong intermolecular or matrix-mediated hydrogen bond networks can generate a synergistic locking effect, but this has rarely been reported in existing designs. In most RTP systems, water molecules typically act as strong polar quenchers, leading to phosphorescence quenching. Few technologies can utilize the hydrogen bond rearrangement between water molecules and supramolecular systems to achieve continuous, reversible, and dynamic control of phosphorescence intensity and emission color, thus limiting its application in humidity sensing.

[0004] Therefore, developing a class of room-temperature phosphorescent materials with pre-embedded multiple hydrogen bonding sites in the guest structure and synergistic effects with cucurbituril assembly and hydrogen-rich matrix to achieve high efficiency and specific humidity response (color change / enhancement) is a technical problem that urgently needs to be solved. Summary of the Invention

[0005] To address the problems of existing pure organic room-temperature phosphorescent materials being prone to quenching in aqueous or high-humidity environments, lacking a sensitive dynamic response mechanism, and having insufficient binding ability of single host-guest interactions to the luminescent body leading to low quantum yield, this invention provides a humidity-responsive room-temperature phosphorescent supramolecular gel, its preparation method, and its application. This material constructs a doubly locked supramolecular assembly (G / CB[8]) by introducing a ureidopyrimidinone (UPy) group with quadruple hydrogen bonding capability and cucurbituril (CB[8]), and achieves efficient room-temperature phosphorescence emission and sensitive response to humidity in a polyvinyl alcohol (PVA) hydrogen-rich network.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: The first objective of this invention is to provide a phenylpyridinium salt derivative G, wherein the phenylpyridinium salt derivative G has multiple hydrogen bonds and its structural formula is shown in I: ; Wherein, R1 is one of F, Cl, Br and I, R2 is a substituted alkyl or unsubstituted alkyl, and n is an integer from 2 to 10; the alkyl group is methyl, ethyl, n-propyl or isopropyl.

[0007] A second objective of this invention is to provide a method for preparing a phenylpyridinium salt derivative G, comprising the following steps: 1) Compound 1, a ureidopyrimidinone derivative, and ethanolamine were added to the mixture at a molar ratio of 1:0.5~4. N,N In dimethylformamide, ethanolamine and N,N The reaction mixture was prepared with dimethylformamide at a volume ratio of 1:15–30, stirred at 10–40 °C for 3–6 h, filtered and washed to obtain compound 2. The chemical equation for the reaction is as follows: ; 2) Add compound 2, bromoacetyl bromide or bromoacetyl chloride, and an organic base to... N,N In dimethylformamide, the reaction is heated at 20–40 °C for 24–48 h, cooled to room temperature, and the organic phase is extracted. The organic phase is then rotary evaporated to obtain compound 3, wherein the molar ratio of compound 2 to bromoacetyl bromide is 1:1–4. Bromoacetyl bromide or bromoacetyl chloride and... N,N -Dimethylformamide in volume ratios of 1:12 to 35, organic base and N,N The volume ratio of dimethylformamide is 1:15~40; the chemical equation for the reaction is as follows: ; 3) Compound 3 and the phenylpyridine derivative were added to an organic solvent in a molar ratio of 1:1~6, wherein the mass ratio of compound 3 to the organic solvent was 1:30~45. The mixture was heated at 60~100 °C for 24~48 h, filtered, and a phenylpyridine salt derivative G with multiple hydrogen bonds was obtained. The chemical equation for the reaction is as follows: .

[0008] Further, in step 1), the detergent used for washing is dimethyl sulfoxide, dichloromethane, or... N,N -Dimethylformamide.

[0009] Further, in step 2), the organic base is at least one of dimethylamine, ethylamine, diethylamine, and triethylamine.

[0010] Further, in step 3), the organic solvent is acetonitrile, dimethyl sulfoxide, N,N - At least one of dimethylformamide and tetrahydrofuran.

[0011] Furthermore, the structural formula of compound 1 is shown in Figure II: ; The structural formula of compound 2 is shown in III: ; The structural formula of compound 3 is shown in IV: ; The structural formula of the phenylpyridine derivative is shown in V: ; In structural formulas II, III, and IV, R2 is a substituted or unsubstituted alkyl group, wherein the alkyl group is methyl, ethyl, n-propyl, or isopropyl; and in structural formula V, R1 is one of F, Cl, Br, and I.

[0012] A third objective of this invention is to provide a method for preparing room-temperature phosphorescent supramolecular gel, comprising the following steps: S1. Prepare aqueous solutions of cucurbit[8]urea and phenylpyridinium salt derivative G respectively; S2. Aqueous solution of cucurbit[8]urea and aqueous solution of phenylpyridinium salt derivative G with multiple hydrogen bonds are mixed in deionized water at a molar ratio of 1:2 between cucurbit[8]urea and phenylpyridinium derivative G, and sonicated to obtain a supramolecular assembly solution, wherein cucurbit[8]urea and phenylpyridinium salt derivative G with multiple hydrogen bonds constitute a supramolecular assembly. S3. The supramolecular assembly solution is added to a 5 wt%~20 wt% polyvinyl alcohol aqueous solution, wherein the mass of the supramolecular assembly in the polyvinyl alcohol aqueous solution is 0.5%~1.5% of the mass of polyvinyl alcohol. The mixture is frozen at -10 ℃ for 8 h, thawed at 25 ℃ for 1 h, and the cycle is repeated 4 times. After freeze-drying, a humidity-responsive room temperature phosphorescent supramolecular gel is prepared.

[0013] The fourth objective of this invention is to provide a humidity-responsive room-temperature phosphorescent supramolecular gel prepared by the preparation method described in the third objective.

[0014] The fifth objective of this invention is to provide a phosphorescent device prepared from the phenylpyridinium salt derivative G or the room-temperature phosphorescent supramolecular gel.

[0015] The sixth objective of this invention is to provide the application of the phenylpyridinium salt derivative G or the room temperature phosphorescent supramolecular gel in humidity sensing, anti-counterfeiting and information encryption.

[0016] Compared with the prior art, the present invention has the following advantages: (1) The present invention induces room temperature phosphorescence emission through the rigid cavity encapsulation effect of CB[8], and effectively suppresses the motion and nonradiative transition of luminescent molecules by constructing a multi-hydrogen bond network between UPy / PVA, thereby significantly improving the quantum yield and stability of organic room temperature phosphorescence.

[0017] (2) By utilizing the competitive disruption of hydrogen bond networks by water molecules, this invention achieves a sensitive response to ambient humidity. As humidity increases, the material's luminescence color shifts significantly from green towards shorter wavelengths, accompanied by a decrease in intensity. This visually perceptible characteristic based on wavelength shift overcomes the limitations of traditional materials that rely solely on intensity quenching for detection, greatly expanding its application in intelligent sensing and anti-counterfeiting fields. Attached Figure Description

[0018] Figure 1 This is a diagram showing the preparation process and visualization results of the humidity-responsive phosphorescent material prepared according to the present invention. Figure 2 The 1H NMR spectrum of 2-(3-(6-methyl-4-oxo-1,4-dihydropyrimidin-2-yl)ureido)ethyl-2-bromoacetate in Example 1; Figure 3 The carbon NMR spectrum of 2-(3-(6-methyl-4-oxo-1,4-dihydropyrimidin-2-yl)ureido)ethyl-2-bromoacetate in Example 1; Figure 4 The 1H NMR spectrum of the phenylpyridinium salt derivative G with multiple hydrogen bonds in Example 1; Figure 5 The carbon NMR spectrum of the phenylpyridinium salt derivative G with multiple hydrogen bonds in Example 1; Figure 6 The UV-Vis absorption spectrum of the aqueous solution of the phenylpyridinium salt derivative G with multiple hydrogen bonds in Example 1 is shown. Figure 7 The fluorescence spectrum of the aqueous solution of the phenylpyridinium salt derivative G with multiple hydrogen bonds in Example 1 is shown. Figure 8 The graph shows the inclusion ratio of G to CB[8] when the total concentration of G and CB[8] is controlled at 0.02 mM in Example 1. Figure 9 The nuclear magnetic resonance spectra of CB[8] and the phenylpyridinium salt derivative G with multiple hydrogen bonds before and after assembly in Example 1; Figure 10 The photoluminescence spectrum of the supramolecular assembly G / CB[8] aqueous solution in Example 1 is shown. Figure 11 The photoluminescence spectrum of the G / CB[8] gel in Example 1 is shown. Figure 12 The time-resolved phosphorescence decay curve of the G / CB[8] gel in Example 1; Figure 13 The phosphorescence emission spectra of G / CB[8] gel in Example 1 at different water contents; Figure 14 These are luminescence photographs of the G / CB[8] gel in Example 1 at different water contents; Figure 15 The time-resolved decay curves of G / CB[8] gels with different water contents in Example 1 are shown. Figure 16 The relationship between the phosphorescence quantum yield of G / CB[8] gel and water content in Example 1 is shown. Figure 17 The images show the luminescence of the G / CB[8] gel in Example 1 under different humidity conditions. Detailed Implementation

[0019] To make the objectives and advantages of this invention clearer, the invention will be specifically described below with reference to embodiments. It should be understood that the following text is merely used to describe one or more specific embodiments of the invention and does not strictly limit the scope of protection specifically claimed by the invention.

[0020] In this invention, no specific alkyl group is limited, and the alkyl group includes methyl, ethyl, n-propyl and isopropyl. Figure 1 This is a diagram showing the preparation process and visualization results of the humidity-responsive phosphorescent material prepared according to the present invention. Example 1 This invention provides a supramolecular assembly based on multiple hydrogen bonding interactions, its preparation method, and its application, comprising the following steps: I. Preparation of phenylpyridinium salt derivative G with multiple hydrogen bonds Step 1: Take 2.54 g N -(4-hydroxy-6-methylpyrimidin-2-yl)-1 H -Imidazole-1-carboxamide and 1.50 mL of ethanolamine were added to 60 mL N,N- The reaction was carried out in dimethylformamide at 25 °C for 6 h, and the mixture was filtered to obtain 2.10 g of a white solid, namely 1-(2-hydroxyethyl)-3-(6-methyl-4-oxo-1,4-dihydropyrimidin-2-yl)urea, with a yield of 85.0%.

[0021] Step 2: Add 2.00 g of 1-(2-hydroxyethyl)-3-(6-methyl-4-oxo-1,4-dihydropyrimidin-2-yl)urea and 2.50 mL of triethylamine to 40 mL of [amount missing]. N,N- In dimethylformamide, 0.91 mL of 2-bromoacetyl bromide was slowly added using a syringe, followed by reaction at 20 °C for 12 h under a helium atmosphere. The mixture was extracted with 40 mL of dichloromethane, washed with 30 mL of water, and dried. The solution was then filtered, concentrated under reduced pressure at 35 °C, recrystallized, and filtered again to obtain 1.91 g of a white solid, 2-(3-(6-methyl-4-oxo-1,4-dihydropyrimidin-2-yl)ureido)ethyl-2-bromoacetate, with a yield of 61.1%. Step 3: 0.51 g of 2-(3-(6-methyl-4-oxo-1,4-dihydropyrimidin-2-yl)ureido)ethyl-2-bromoacetate and 0.75 g of 4-(4-bromophenyl)pyridine were added to 30 mL of acetonitrile; then the mixture was heated to 85 °C, stirred and refluxed for 48 h, cooled to room temperature and filtered. The solid was washed twice with 5 mL of dichloromethane and dried to obtain a light brown solid, namely 0.56 g of phenylpyridine salt derivative G with multiple hydrogen bonds, with a yield of 64.5%.

[0022] II. Preparation and photophysical properties of supramolecular assembly G / CB[8] solution Step 4: Take the phenylpyridinium salt derivative G obtained in Step 3 (5×10) -5 mmol was dissolved in 5 mL of deionized water to obtain a phenylpyridine derivative solution with multiple hydrogen bonds; Cucurbita[8]urea 5×10 -4 mmol was dissolved in 5 mL of deionized water to obtain cucurbit[8]urea solution; According to the molar ratio of cucurbit[8]urea: phenylpyridine derivative G=1:2, the corresponding cucurbit[8]urea solution was added to the phenylpyridine derivative solution with multiple hydrogen bonds, and ultrasonic treatment (30℃, 5 minutes) was performed to obtain the supramolecular assembly G / CB[8] aqueous solution.

[0023] Step 5: Photoluminescence and phosphorescence spectra of the supramolecular assembly G / CB[8] aqueous solution from step 4 were tested using a fluorescence spectrometer, and the quantum yield was calculated. The concentration of the phenylpyridinium salt derivative G was 1.0 × 10⁻⁶. -5 M. Among them, the photoluminescence quantum yield of the supramolecular assembly G / CB[8] was 2.02%, and the phosphorescence quantum yield was 0.98%.

[0024] Figure 2 and Figure 3 The images show the 1H and 1C NMR spectra of 2-(3-(6-methyl-4-oxo-1,4-dihydropyrimidin-2-yl)ureido)ethyl-2-bromoacetate, respectively. Figure 4 and Figure 5 The images show the hydrogen and carbon NMR spectra of the phenylpyridinium salt derivative G with multiple hydrogen bonds, respectively.

[0025] The UV-Vis absorption spectrum of the supramolecular assembly G / CB[8] aqueous solution is shown below. Figure 6 As shown, its characteristic absorption peak is located at 308 nm.

[0026] The fluorescence spectrum of the supramolecular assembly G / CB[8] in aqueous solution is shown below. Figure 7 As shown, its fluorescence emission peak is located at 380 nm.

[0027] Figure 8 To control the total concentration of cucurbit[8]urea and phenylpyridinium salt derivative G at 0.02 mM, the inclusion ratio of phenylpyridinium salt derivative G to cucurbit[8]urea was determined. As shown in the figure, the abscissa corresponding to the highest point of the Job's Plot curve of CB[8] and G is 0.67, indicating that CB[8] and G form a supramolecular assembly G / CB[8] in an aqueous solution with a stoichiometric ratio of 1:2.

[0028] Figure 9 The figure shows the NMR titration of CB[8] with phenylpyridinium salt derivative G. The figure indicates that after CB[8] binds to phenylpyridinium salt derivative G in stoichiometric proportions, the protons H on the two benzene rings of phenylpyridinium salt derivative G... a H b H c H dAll of them clearly shifted to higher fields, with chemical shifts of 0.22 ppm, 0.95 ppm, 0.91 ppm, and 1.09 ppm, respectively. This indicates that both benzene rings of the phenylpyridinium salt derivative G are located deep within the host cavity.

[0029] Figure 10 The photoluminescence spectrum of the supramolecular assembly G / CB[8] aqueous solution is shown in the figure. As shown in the figure, after G and CB[8] are assembled, a new emission peak is induced at 510 nm, and its radiation lifetime is 0.58 ms, indicating that it is phosphorescent emission.

[0030] III. Preparation methods and photophysical properties of G / CB[8] gel Step 6: Prepare a 10 wt% polyvinyl alcohol aqueous solution. Add the supramolecular assembly G / CB[8] from step 4 to the polyvinyl alcohol aqueous solution at 1.0% relative to the mass of polyvinyl alcohol. After mixing evenly, freeze at -10 ℃ for 8 h, melt at 25 ℃ for 1 h, repeat 4 times, and freeze-dry to obtain a humidity-responsive room temperature phosphorescent supramolecular gel (G / CB[8] gel).

[0031] Step 7: The room temperature phosphorescent supramolecular gel with multiple humidity responses from Step 6 was subjected to phosphorescence spectroscopy and the quantum yield was calculated. The phosphorescence quantum yield of the G / CB[8] gel was 18.84%, which was 19.2 times higher than that of the supramolecular assembly G / CB[8] solution.

[0032] Figure 11 The photoluminescence spectrum of G / CB[8] gel is shown. The comparison results show that the phosphorescence emission peak intensity is significantly enhanced after the supramolecular assembly G / CB[8] aqueous solution is introduced into the polyvinyl alcohol matrix to form a gel. This enhancement effect is attributed to the dense hydrogen bond network in the gel effectively restricting the nonradiative transition of guest molecules, thereby promoting efficient phosphorescence radiation.

[0033] Figure 12 The time-resolved phosphorescence decay curve of the G / CB[8] gel is shown. The supramolecular gel has an average phosphorescence lifetime of 4.98 ms at 510 nm, which is 8.6 times longer than that of the assembled G / CB[8] aqueous solution, confirming the effective stabilizing effect of gelation on triplet excitons.

[0034] Figure 13 The phosphorescence emission spectra of G / CB[8] gel at different water contents are shown in the figure. As the water content in the system increases, the intensity of the phosphorescence emission peak shows a significant decreasing trend. This phenomenon is attributed to the competitive destruction of the hydrogen bond network inside the gel by water molecules, which weakens the rigid binding of guest molecules and thus exacerbates the nonradiative transition dissipation.

[0035] Figure 14The images show the luminescence of G / CB[8] gel at different water contents. The figures show that as the water content increases, the luminescence color of the gel changes from green to blue.

[0036] Figure 15 Time-resolved decay curves of G / CB[8] gels with different water contents are shown. The data show that as the water content in the system increases, the excited-state lifetime of the samples shows a regular shortening trend.

[0037] Figure 16 The relationship between the phosphorescence quantum yield of G / CB[8] gel and water content is shown. The data indicate that water molecules, acting as polar quenchers, disrupt the hydrogen bond network, resulting in a significant decrease in phosphorescence quantum yield with increasing water content.

[0038] Figure 17 The images show the luminescence of G / CB[8] gel under different humidity conditions. The results show that the material can produce a sensitive color response to changes in ambient humidity, and achieves dynamic switching from green to blue, indicating that it has good humidity detection and imaging performance.

[0039] Example 2: Preparation of phenylpyridinium salt derivative G with multiple hydrogen bonds The synthesis conditions of the phenylpyridinium salt derivative G in Example 1 were changed, specifically by changing the feed ratio in step 1, and the following steps were performed sequentially: Step 1: Replace "1.50 mL ethanolamine" in Step 1 of Example 1 with "1.10 mL ethanolamine", and the rest is the same as Step 1 of Example 1. 1.74 g of a white solid, namely 1-(2-hydroxyethyl)-3-(6-methyl-4-oxo-1,4-dihydropyrimidin-2-yl)urea, was obtained, with a yield of 70.3%.

[0040] Step 1 is the same as Step 1 in Example 1.

[0041] Step 3 is the same as step 3 in Example 1.

[0042] Example 3: Preparation of phenylpyridinium salt derivative G with multiple hydrogen bonds The synthesis conditions of the phenylpyridinium salt derivative G in Example 1 were changed, specifically by changing the reaction temperature in step 1, and the following steps were performed sequentially: Step 1: Change "react at 25 °C for 6 h" in Step 1 of Example 1 to "react at 10 °C for 6 h", the rest is the same as Step 1 of Example 1. 1.91 g of a white solid, namely 1-(2-hydroxyethyl)-3-(6-methyl-4-oxo-1,4-dihydropyrimidin-2-yl)urea, was obtained, with a yield of 77.3%.

[0043] Step 1 is the same as Step 1 in Example 1.

[0044] Step 3 is the same as step 3 in Example 1.

[0045] Example 4: Preparation of phenylpyridinium salt derivative G with multiple hydrogen bonds The synthesis conditions of the phenylpyridinium salt derivative G in Example 1 were changed, specifically by changing the reaction temperature in step 1, and the following steps were performed sequentially: Step 1: Change "react at 25 °C for 6 h" in Step 1 of Example 1 to "react at 40 °C for 6 h", the rest is the same as Step 1 of Example 1. 2.00 g of a white solid, namely 1-(2-hydroxyethyl)-3-(6-methyl-4-oxo-1,4-dihydropyrimidin-2-yl)urea, was obtained, with a yield of 81.2%.

[0046] Step 1 is the same as Step 1 in Example 1.

[0047] Step 3 is the same as step 3 in Example 1.

[0048] Example 5: Preparation of phenylpyridinium salt derivative G with multiple hydrogen bonds The synthesis conditions of the phenylpyridinium salt derivative G in Example 1 were changed, specifically by changing the feed ratio in step 2, and the following steps were performed sequentially: Step 1 is the same as Step 1 in Example 1.

[0049] Step 2: Replace "0.91 mL 2-bromoacetyl bromide" in Step 2 of Example 1 with "0.72 mL 2-bromoacetyl bromide", and the rest is the same as Step 2 of Example 1. 1.76 g of a white solid, 2-(3-(6-methyl-4-oxo-1,4-dihydropyrimidin-2-yl)ureido)ethyl-2-bromoacetate, was obtained, with a yield of 56.5%.

[0050] Step 3 is the same as step 3 in Example 1.

[0051] Example 6: Preparation of phenylpyridinium salt derivative G with multiple hydrogen bonds The synthesis conditions of the phenylpyridinium salt derivative G in Example 1 were changed, specifically by changing the reaction temperature in step 2, and the following steps were performed sequentially: Step 1 is the same as Step 1 in Example 1.

[0052] Step 2: Replace "2-bromoacetyl bromide" with "2-bromoacetyl chloride" in Step 2 of Example 1, and the rest is the same as Step 2 of Example 1. 1.43 g of a white solid, namely 2-(3-(6-methyl-4-oxo-1,4-dihydropyrimidin-2-yl)ureido)ethyl-2-bromoacetate, was obtained, with a yield of 47.1%.

[0053] Step 3 is the same as step 3 in Example 1.

[0054] Example 7: Preparation of phenylpyridinium salt derivative G with multiple hydrogen bonds The synthesis conditions of the phenylpyridinium salt derivative G in Example 1 were changed, specifically by changing the reaction temperature in step 2, and the following steps were performed sequentially: Step 1 is the same as Step 1 in Example 1.

[0055] Step 2: Change "react at 20 °C for 12 h" in Step 2 of Example 1 to "react at 30 °C for 12 h", the rest is the same as Step 2 of Example 1. 1.65 g of a white solid, namely 2-(3-(6-methyl-4-oxo-1,4-dihydropyrimidin-2-yl)ureido)ethyl-2-bromoacetate, was obtained, with a yield of 54.5%.

[0056] Step 3 is the same as step 3 in Example 1.

[0057] Example 8: Preparation of phenylpyridinium salt derivative G with multiple hydrogen bonds The synthesis conditions of the phenylpyridinium salt derivative G in Example 1 were changed, specifically by changing the reaction temperature in step 2, and the following steps were performed sequentially: Step 1 is the same as Step 1 in Example 1.

[0058] Step 2: Change "react at 20 °C for 12 h" in Step 2 of Example 1 to "react at 40 °C for 12 h", the rest is the same as Step 2 of Example 1. 1.50 g of a white solid, namely 2-(3-(6-methyl-4-oxo-1,4-dihydropyrimidin-2-yl)ureido)ethyl-2-bromoacetate, was obtained, with a yield of 49.5%.

[0059] Step 3 is the same as step 3 in Example 1.

[0060] Example 9: Preparation of phenylpyridinium salt derivative G with multiple hydrogen bonds The synthesis conditions of the phenylpyridinium salt derivative G in Example 1 were changed, specifically by changing the organic base in step 2, and the following steps were performed sequentially: Step 1 is the same as Step 1 in Example 1.

[0061] Step 2: Replace "triethylamine" with "diethylamine" in Step 2 of Example 1, and the rest is the same as Step 2 of Example 1. 0.84 g of a white solid, namely 2-(3-(6-methyl-4-oxo-1,4-dihydropyrimidin-2-yl)ureido)ethyl-2-bromoacetic acid ester, was obtained, with a yield of 26.6%.

[0062] Step 3 is the same as step 3 in Example 1.

[0063] Example 10: Preparation of phenylpyridinium salt derivative G with multiple hydrogen bonds The synthesis conditions of the phenylpyridinium salt derivative G in Example 1 were changed, specifically by changing the feed ratio in step 3, and the following steps were performed sequentially: Step 1 is the same as Step 1 in Example 1.

[0064] Step 2 is the same as step 2 in Example 1.

[0065] Step 3: Replace "0.75 g 4-(4-bromophenyl)pyridine" in Step 3 of Example 1 with "0.50 g 4-(4-bromophenyl)pyridine", and the rest is the same as Step 3 of Example 1. A light brown solid, namely the phenylpyridine salt derivative G with multiple hydrogen bonds, is obtained in 0.37 g, with a yield of 43.0%.

[0066] Example 11: Preparation of phenylpyridinium salt derivative G with multiple hydrogen bonds The synthesis conditions of the phenylpyridinium salt derivative G in Example 1 were changed, specifically by changing the reaction temperature in step 3, and the following steps were performed sequentially: Step 1 is the same as Step 1 in Example 1.

[0067] Step 2 is the same as step 2 in Example 1.

[0068] Step 3: In Example 1, step 3, "stirring and refluxing at 85 °C for 48 h" is changed to "stirring and refluxing at 60 °C for 48 h", and the rest is the same as in Example 1, step 3. A light brown solid, namely the phenylpyridinium salt derivative G with multiple hydrogen bonds, is obtained in 0.42 g, with a yield of 48.8%.

[0069] Example 12: Preparation of phenylpyridinium salt derivative G with multiple hydrogen bonds The synthesis conditions of the phenylpyridinium salt derivative G in Example 1 were changed, specifically by changing the reaction temperature in step 3, and the following steps were performed sequentially: Step 1 is the same as Step 1 in Example 1.

[0070] Step 2 is the same as step 2 in Example 1.

[0071] Step 3: In Example 1, step 3, "stirring and refluxing at 85 °C for 48 h" is changed to "stirring and refluxing at 100 °C for 48 h", and the rest is the same as in Example 1, step 3. A light brown solid, namely the phenylpyridinium salt derivative G with multiple hydrogen bonds, is obtained in 0.43 g, with a yield of 51.1%.

[0072] Example 13: Preparation of phenylpyridinium salt derivative G with multiple hydrogen bonds The synthesis conditions of the phenylpyridinium salt derivative G in Example 1 were changed, specifically by changing the organic solvent in step 3, and the following steps were performed sequentially: Step 1 is the same as Step 1 in Example 1.

[0073] Step 2 is the same as step 2 in Example 1.

[0074] Step 3: Replace "30 mL acetonitrile" with "30 mL dimethyl sulfoxide" in Step 3 of Example 1, and the rest is the same as Step 3 of Example 1. A light brown solid, namely the phenylpyridinium salt derivative G with multiple hydrogen bonds, was obtained in 0.38 g, with a yield of 44.8%.

[0075] Example 14: Preparation method and photophysical properties of G / CB[8] gel The synthesis conditions of G / CB[8] gel in Example 1 were changed, specifically the ratio of supramolecular assembly G / CB[8] to polyvinyl alcohol in step 6 was changed: Step 6: Change "1.0% relative to the mass of polyvinyl alcohol" in Step 6 of Example 1 to "0.5% relative to the mass of polyvinyl alcohol", and the rest is the same as Step 6 in Example 1.

[0076] Phosphorescence spectroscopy measurements showed that its radiation lifetime was 3.92 ms and its phosphorescence quantum yield was 13.89%.

[0077] Example 15: Preparation method of G / CB[8] gel and its photophysical properties The synthesis conditions of G / CB[8] gel in Example 1 were changed, specifically the ratio of supramolecular assembly G / CB[8] to polyvinyl alcohol in step 6 was changed: Step 6: Change "1.0% relative to the mass of polyvinyl alcohol" in Step 6 of Example 1 to "1.5% relative to the mass of polyvinyl alcohol", and the rest is the same as Step 6 in Example 1.

[0078] Phosphorescence spectroscopy measurements showed that its radiation lifetime was 4.84 ms and its phosphorescence quantum yield was 10.86%.

[0079] Based on the results of the above examples, the guest molecule G prepared in Example 1 has the highest yield, and the supramolecular gel constructed from it exhibits the best room temperature phosphorescence performance, with a phosphorescence lifetime of 4.98 ms and a phosphorescence quantum yield of 18.84%, which is significantly better than other examples.

[0080] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. 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. A phenylpyridinium salt derivative G, characterized in that, The phenylpyridinium salt derivative G has multiple hydrogen bonds, and its structural formula is shown in I: ； Wherein, R1 is one of F, Cl, Br and I, R2 is a substituted alkyl or unsubstituted alkyl, and n is an integer from 2 to 10; the alkyl group is methyl, ethyl, n-propyl or isopropyl.

2. A method for preparing the phenylpyridinium salt derivative G according to claim 1, characterized in that, Includes the following steps: 1) Add ureidopyrimidinone derivative compound 1 and ethanolamine in a molar ratio of 1:0.5~4 to... N,N In dimethylformamide, ethanolamine and N,N The volume ratio of dimethylformamide was 1:15-30, and the reaction was stirred at 10-40 °C for 3-6 h. After filtration and washing, compound 2 was obtained. 2) Add compound 2, bromoacetyl bromide or bromoacetyl chloride, and an organic base to... N,N In N,N-dimethylformamide, the mixture is heated at 20–40 °C for 24–48 h, cooled to room temperature, and the organic phase is extracted. The organic phase is then rotary evaporated to obtain compound 3. The molar ratio of compound 2 to bromoacetyl bromide or bromoacetyl chloride is 1:1–4, the volume ratio of bromoacetyl bromide or bromoacetyl chloride to N,N-dimethylformamide is 1:12–35, and the volume ratio of organic base to N,N-dimethylformamide is 1:15–40. 3) Compound 3 and the phenylpyridine derivative were added to an organic solvent in a molar ratio of 1:1 to 6, wherein the mass ratio of compound 3 to the organic solvent was 1:30 to 45. The mixture was heated at 60 to 100 °C for 24 to 48 h and filtered to obtain a phenylpyridine salt derivative G with multiple hydrogen bonds.

3. The preparation method according to claim 2, characterized in that, In step 1), the detergent used for washing is dimethyl sulfoxide, dichloromethane, or... N,N -Dimethylformamide.

4. The preparation method according to claim 2, characterized in that, In step 2), the organic base is at least one of dimethylamine, ethylamine, diethylamine and triethylamine.

5. The preparation method according to claim 2, characterized in that, In step 3), the organic solvent is acetonitrile, dimethyl sulfoxide, N,N - At least one of dimethylformamide and tetrahydrofuran.

6. The preparation method according to claim 2, characterized in that, The structural formula of compound 1 is shown in II: ； The structural formula of compound 2 is shown in III: ； The structural formula of compound 3 is shown in IV: ； The structural formula of the phenylpyridine derivative is shown in V: ； In structural formulas II, III, and IV, R2 is a substituted alkyl or an unsubstituted alkyl, wherein the alkyl is methyl, ethyl, n-propyl, or isopropyl; and in structural formula V, R1 is one of F, Cl, Br, and I.

7. A method for preparing a room-temperature phosphorescent supramolecular gel, characterized in that, Includes the following steps: S1. Prepare aqueous solutions of cucurbit[8]urea and phenylpyridinium salt derivative G respectively; S2. Aqueous solution of cucurbit[8]urea and aqueous solution of phenylpyridinium salt derivative G with multiple hydrogen bonds are mixed in deionized water at a molar ratio of 1:2 between cucurbit[8]urea and phenylpyridinium derivative G, and sonicated to obtain a supramolecular assembly solution, wherein cucurbit[8]urea and phenylpyridinium salt derivative G with multiple hydrogen bonds constitute a supramolecular assembly. S3. The supramolecular assembly solution is added to a 5 wt%~20 wt% polyvinyl alcohol aqueous solution, wherein the mass of the supramolecular assembly in the polyvinyl alcohol aqueous solution is 0.5%~1.5% of the mass of polyvinyl alcohol. The mixture is frozen at -10 ℃ for 8 h, thawed at 25 ℃ for 1 h, and the cycle is repeated 4 times. After freeze-drying, a humidity-responsive room temperature phosphorescent supramolecular gel is prepared.

8. A humidity-responsive room-temperature phosphorescent supramolecular gel prepared by the preparation method of claim 7.

9. A phosphorescent device, characterized in that, It is prepared from the phenylpyridinium salt derivative G of claim 1 or the room temperature phosphorescent supramolecular gel of claim 8.

10. The application of the phenylpyridinium salt derivative G of claim 1 or the room temperature phosphorescent supramolecular gel of claim 8 in humidity sensing, anti-counterfeiting and information encryption.

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