Application of a polynary nitrogen heterocyclic triphenylamine compound as a luminescent material

Abstract

The present invention discloses an application of a polynary nitrogen heterocyclic triphenylamine compound as a luminescent material, wherein the polynary nitrogen heterocyclic triphenylamine compound can undergo an isomerization process in a solution at 25°C to 95°C, accompanied by corresponding changes in color and fluorescence, and the fluorescence changes from green to blue as the temperature rises. The compound can be used in the fields of information display, light patterning and anti-counterfeiting.

Description

Technical Field

[0001] The invention belongs to the technical field of organic luminescent materials, and in particular relates to the application of a polynary nitrogen heterocyclic triphenylamine compound as a luminescent material. Background Art

[0002] Fluorescent materials have attracted much attention in recent years due to their wide applications in optoelectronic devices, chemical / biosensing and bioimaging. Traditional luminescent molecules are planar conjugated compounds that can emit bright light in dilute solutions, but the luminescence is significantly weakened or even completely quenched in the aggregated state. This phenomenon is called aggregation-induced quenching (ACQ). ACQ is a common phenomenon of traditional fluorescent materials and urgently needs to be broken through by scientific and convenient means. The phenomenon of showing strong luminescence in the aggregated or solid state, but no luminescence or weak luminescence in the dissolved state is called aggregation-induced emission effect (AIE). TPA and its derivatives have been widely and deeply studied because of their easy modification, easy functionalization and excellent AIE properties. The AIE concept has opened up a new path for the design and synthesis of fluorescent materials and has been successfully applied to the fields of organic electroluminescence (OLED), chemical sensing, stimulus response systems, etc. However, how to effectively control the optical properties of fluorophores through temperature parameters to promote the development of advanced functional optical materials and explore their application potential is still a great challenge. Therefore, the development of multifunctional aggregation-induced emission materials with tunable optical properties is very necessary. Summary of the invention

[0003] The present invention provides an application of an aggregation-induced luminescent material whose color can be adjusted with temperature, which can undergo an isomerization process in a solution at 25°C to 95°C, accompanied by corresponding changes in color and fluorescence. The fluorescence of the aggregation-induced luminescent material changes from green to blue as the temperature increases. The aggregation-induced luminescent material can be used in the fields of information display, light patterning and anti-counterfeiting.

[0004] In order to achieve the above-mentioned invention purpose, the following technical route is adopted:

[0005] A polynary nitrogen heterocyclic triphenylamine compound is used as an organic light-emitting material, and the polynary nitrogen heterocyclic triphenylamine compound has the following structure:

[0006]

[0007] Wherein R is phenyl or triphenyl.

[0008] Preferably, the polynary nitrogen heterocyclic triphenylamine compound is used as a condensed light-emitting material.

[0009] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention provides the application of a polynary nitrogen heterocyclic triphenylamine compound as an organic light-emitting material. The condensed state light-emitting material provided by the present invention is a polynary nitrogen heterocyclic compound having a carbon-nitrogen resonance effect. By introducing a nitrogen-containing heterocyclic ring with a Schiff base structure, the designed compound molecule has condensed state light-emitting properties, a narrow half-peak width of the fluorescence emission spectrum, and a light-emitting color that can cover the entire color range without destroying the original resonance structure. In addition, the color of the fluorescence emission of the material in the solution changes from green to blue as the temperature increases. This type of condensed state light-emitting material whose color can be adjusted with temperature has broad application prospects in information storage, anti-counterfeiting, sensor display, and the like.

[0010] It should be understood that all combinations of the aforementioned concepts and the additional concepts described in more detail below can be considered as part of the inventive subject matter of the present application as long as such concepts are not mutually contradictory. In addition, all combinations of the claimed subject matter are considered as part of the inventive subject matter of the present application.

[0011] The foregoing and other aspects, embodiments and features of the present invention can be more fully understood from the following description in conjunction with the accompanying drawings. Other additional aspects of the present invention, such as the features and / or beneficial effects of the exemplary embodiments, will be apparent from the following description or learned from the practice of the specific embodiments according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 UV-visible absorption spectra of (a) compound film and (b) in ethanol solution, (c) compound in 0.5MLiClO4 / PC solution at a scanning speed of 100mv s -1 CV curve when .

[0013] Figure 2 Molecular stereogram showing the HOMO / LUMO wave function distribution of the compound.

[0014] Figure 3 Fluorescence excitation spectra of (a) compound 1 and (b) compound 2 in ethanol solution, film and solid, respectively. Figure 4 (a) Fluorescence emission spectra of compound 1 and (b) compound 2 in EA solution, film and solid, respectively, (c) CIE 1931 (x, y) chromaticity diagram of compound 1 and (d) compound 2, (e) fluorescence diagram of compound 1 solution, film and solid, (f) fluorescence diagram of compound 2 solution, film and solid.

[0015] Figure 5 (a) Compound 1 and (b) Compound 2 (1.0×10 -6 M) Fluorescence emission spectrum in EA / water mixture, λex (Compound 1) = 383 nm, λ ex (Compound 2) = 390 nm, (c) fluorescence spectra of DMF dilute solutions of Compound 1 and (d) Compound 2 as the temperature changes, (e) CIE chromaticity diagram (x, y) color coordinates of Compound 1 and (f) Compound 2. DETAILED DESCRIPTION

[0016] In order to better understand the technical content of the present invention, specific embodiments are given and described as follows in conjunction with the accompanying drawings.

[0017] Various aspects of the present invention are described herein with reference to the accompanying drawings, in which many illustrative embodiments are shown. Embodiments of the present invention are not necessarily intended to include all aspects of the present invention. It should be understood that the various concepts and embodiments introduced above, as well as those described in more detail below, can be implemented in any of many ways, because the concepts and embodiments disclosed by the present invention are not limited to any implementation. In addition, some aspects disclosed by the present invention can be used alone, or in any appropriate combination with other aspects disclosed by the present invention.

[0018] The embodiment of the present invention provides a polynary nitrogen heterocyclic triphenylamine compound, the structural formula of which is as follows:

[0019]

[0020] The present invention uses isolongifolia alkane Ⅰ as a starting material, activates its ortho-CH bond under the catalytic action of an alkaline catalyst, and then undergoes a nucleophilic substitution reaction with an aromatic aldehyde to obtain the intermediate Ⅱ shown, and the intermediate Ⅱ undergoes a cyclization reaction with guanidine hydrochloride to obtain the intermediate Ⅲ, and the intermediate Ⅲ reacts with 4-diphenylaminobenzaldehyde to obtain a quinazoline derivative. The synthetic route is as follows:

[0021]

[0022] The present invention is illustrated by the following examples, which are only used for illustration and cannot be regarded as limiting the scope of the invention or the application method of the invention. Unless otherwise specified, the raw materials of the present invention are commercially available.

[0023] Example 1

[0024] The complete route for the synthesis of compound 1 is as follows:

[0025]

[0026] The specific synthesis steps are:

[0027] 10g (0.045mol) of iso-longifolia alkane, 6.35g (0.060mol) of benzaldehyde, 2.2g (0.020mol) of potassium tert-butoxide and 50mL of tert-butanol were added to a 100mL single-necked flask in sequence, and reacted at 70°C for 2h. After the reaction was completed, the reaction solution was cooled to room temperature. The reaction solution was used to remove the solvent by rotary evaporation, and the insoluble matter was collected. The insoluble matter was dissolved in a large amount of ethyl acetate, washed with water, dried over anhydrous sodium sulfate, filtered and collected, and the filtrate was rotary evaporated until the solvent was completely evaporated to obtain a crude intermediate 1. The crude intermediate 1 was recrystallized, filtered, and dried to obtain intermediate 1, namely (E)-7-benzylidene-1,1,5,5-tetramethyl-hexahydropyridine-1H-2,4a-methylene-8(2H)-naphthalenone (12.5g, light yellow solid, yield 89.0%). 1 H NMR(600MHz, CDCl3)δ7.53(s,1H),7.48-7.48(d,2H),7.41-7.39(t,2H),7.34-7.32 (t,1H),2.85-2.84(d,1H),2.64(s,1H),1.99(s,1H),1.85-1.87(m,1H),1.82(s,1H ),1.80-1.81(d,1H),1.77-1.78(d,1H),1.65-1.66(d,1H),1.51-1.55(m,1H),1.30 -1.32(d,1H),1.25(s,3H),1.06(s,3H),0.88(s,3H),0.86(s,3H).HRMS(ESI)m / z:C 22 H 28 O, theoretical value: 308.21; measured value: 309.22 [M+H] + .

[0028] Add intermediate 1 (2.8 g), guanidine hydrochloride 3.8 g (0.040 mol), potassium tert-butoxide 2.2 g (0.020 mol) and tert-butanol 50 mL into a 100 mL three-necked flask, react at 70 ° C for 6 hours, and cool the reaction solution to room temperature after the reaction is completed. Dissolve the reaction solution in a large amount of ethyl acetate, wash with water, dry with anhydrous sodium sulfate, collect the filtrate by filtration, and evaporate until the solvent is completely evaporated to obtain a crude intermediate 2. The crude intermediate 2 is recrystallized, filtered and dried to obtain intermediate 2, i.e., 6,6,10,10-tetramethyl-4-phenyl-6,7,8,9,10,10a-hexahydro-5H-6a,9-methylbenz[H]quinazolin-2-amine (1.89 g, yield 60.0%). 1HNMR(600MHz, CDCl3)δ7.53(s,1H),7.49(d,1H),7.48(s,1H),7.41-7.43(t,2H),7.40(s,1H),1.26(s,1H),1.24(s,3H), 1.20(s,1H),1.06(s,3H),0.98(s,2H),0.97(s,1H),0.96(s,2H),0.92(s,2H),0.88(s,3H),0.85(s,3H).HRMS(ESI)m / z:C 23 H 29 N3, theoretical value: 347.24; measured value: 348.24 [M+H] + .

[0029] Intermediate 2 (0.400 g), 4-(N,N-diphenylamino)benzaldehyde 0.273 g (0.1 mmol g) and ethanol 30 mL were mixed evenly and poured into a 100 mL three-necked flask. The mixture was refluxed at 78 °C for 12 h under nitrogen protection. After the reaction was completed, the solvent was removed by rotary evaporation to obtain a solid crude product. The crude product was purified by recrystallization to obtain compound 1, namely ((E)-N-(4-(diphenylamino)benzylidene)-6,6,10,10-tetramethyl-4-phenyl-6,7,8,9,10,10a-hexahydro-5H-6a,9-methylbenz[H]quinazolin-2-amine). 1HNMR (600MHz, CDCl3, δ, ppm): 9.808 (s, 1H, CH), 7.681-7.684 (d, J = 1.8Hz, 1H, Ar-H),7.670-7.673(d,J=1.8Hz,1H,Ar-H),7.528(s,1H,Ar-H),7.489(s,1H,A r-H),7.477(s,1H,Ar-H),7.387-7.413(t,J=15.6Hz,2H,Ar-H),7.354(s,1H, Ar-H),7.342(s,2H,Ar-H),7.328(s,2H,Ar-H),7.181(s,3H,Ar-H),7.170(s,1 H,Ar-H),7.168(s,2H,Ar-H),7.022(s,1H,Ar-H),7.008(s,1H,CH),1.989-1. 992(d,J=1.8Hz,1H,CH),1.775-1.782(d,J=2.7Hz,1H,CH),1.586(s,3H,CH),1 .317-1.319(d,1H,J=1.2Hz,CH),1.303(s,1H,CH),1.257(s,2H,CH),1.246(s, 3H,CH),1.062(s,3H,CH),0.883(s,3H,CH),0.855(s,3H,CH).HRMS(ESI)m / z:C 42 H 42 N4, theoretical value: 603.34; measured value: 603.35[M+] + .

[0030] Example 2

[0031] The complete route for the synthesis of compound 2 is as follows:

[0032]

[0033] The specific synthesis steps are:

[0034] Iso-longifolia alkane (10 g), 4-(N,N-diphenylamino)benzaldehyde 0.273 g (0.001 mol), potassium tert-butoxide (2.2 g) and tert-butanol (50 mL) were added to a 100 mL single-necked flask in sequence, and reacted at 70°C for 2 h. After the reaction was completed, the reaction solution was cooled to room temperature. The reaction solution was used to remove the solvent by rotary evaporation, and the insoluble matter was collected. The insoluble matter was dissolved in a large amount of ethyl acetate, washed with water, dried over anhydrous sodium sulfate, filtered and collected, and the filtrate was rotary evaporated until the solvent was completely evaporated to obtain a crude intermediate 3. The crude intermediate 3 was recrystallized, filtered, and dried to obtain intermediate 3, namely (E)-7-(4-(diphenylamine)benzylidene)-1,1,5,5-tetramethylhexahydro-1H-2,4a-methylene-8(2H)-naphthalenone. 1 H NMR(600MHz,CDCl3,δ,ppm):7.395(s,1H,Ar-H),7.381(s,1H,Ar-H),7.293-7 .296(d,J=1.8Hz,1H,Ar-H),7.283(s,2H,Ar-H),7.270(s,1H,Ar-H),7.144(s ,1H,Ar-H),7.136(s,1H,Ar-H),7.124(s,1H,Ar-H),7.088(s,1H,Ar-H),7.07 6(s,1H,Ar-H),7.063-7.065(d,J=1.2Hz,1H,Ar-H),7.046(s,1H,Ar-H),7.038 (s,1H,Ar-H),7.023(s,1H,CH),1.973-1.976(d,J=1.8Hz,2H,CH),1.860(s,1 H,CH),1.755-1.762(d,J=4.2Hz,1H,CH),1.294-1.298(d,J=2.4Hz,1H,CH),1. 255-1.259(d,J=2.4Hz,1H,CH),1.235(s,3H,CH),1.058(s,3H,CH),0.955(s, 2H,CH),0.874(s,3H,CH),0.860(s,3H,CH),0.847(s,2H,CH).HRMS(ESI)m / z:C 34 H 37 NO, theoretical value: 475.29; measured value: 476.30 [M+H] + .

[0035] Add intermediate 3 (2.8 g), guanidine hydrochloride (3.8 g), potassium tert-butoxide 2.2 g (0.020 mol) and tert-butanol 50 mL into a 100 mL three-necked flask, react at 70 ° C for 6 hours, and cool the reaction solution to room temperature after the reaction is completed. Dissolve the reaction solution in a large amount of ethyl acetate, wash with water, dry with anhydrous sodium sulfate, collect the filtrate by filtration, and evaporate until the solvent is completely evaporated to obtain a crude intermediate 4. The crude intermediate 4 is recrystallized, filtered and dried to obtain intermediate 4, namely 4-(4-(diphenylamine)phenyl)-6,6,10,10-tetramethyl-6,7,8,9,10,10a-hexahydro-5H-6a,9-methylbenz[H]quinazolin-2-amine. 1 H NMR (600MHz, CHCl3, δ, ppm): 7.451 (s, 1H, Ar-H), 7.436 (s, 1H, Ar-H), 7.290-7.294 (d, J = 2.4Hz, 2H, Ar-H), 7.276 (s, 2H, Ar-H ),7.155(s,2H,Ar-H),7.142(s,2H,Ar-H),7.106(s,1H,Ar-H),7.092(s,1H,Ar-H),7.069(s,1H,Ar-H),7.056(s,2H,CH),7. 045-7.046(d,J=0.6Hz,1H,Ar-H),4,816(s,2H,NH),2.313(s,1H,CH),1.747(s,2H,CH),1.372(s,3H,CH),1.275(s,1H,CH), 1.255(s,2H,CH),1.236(s,1H,CH),1.215(s,1H,CH),1.010(s,3H,CH),0.770(s,3H,CH),0.679(s,3H,CH).HRMS(ESI)m / z: C 35 H 38 N4, theoretical value: 514.31; measured value: 515.32 [M+H] + .

[0036] Intermediate 4 (0.400 g), 4-(N,N-diphenylamino)benzaldehyde 0.273 g (0.001 mol) and ethanol 30 mL were mixed evenly and poured into a 100 mL three-necked flask. The mixture was refluxed at 78 °C for 12 h under nitrogen protection. After the reaction, the solvent was removed by rotary evaporation to obtain a solid crude product. The crude product was purified by recrystallization to obtain compound 2, namely (E)-N-(4-(diphenylamino)benzylidene)-4-(4-(diphenylamino)phenyl)-6,6,10,10-tetramethyl-6,7,8,9,10,10a-hexahydro-5H-6a,9-methylbenz[H]quinazolin-2-amine. 1H NMR (600MHz, CDCl3, δ, ppm): 9.806 (s, 1H, Ar-H), 7.668-7.682 (s, J = 8.4Hz, 1H, Ar-H), 7.457 (s, 2H ,Ar-H),7.395(s,2H,Ar-H),7.381(s,2H,Ar-H),7.351(s,1H,Ar-H),7.338(s,1H,Ar-H),7.325(s ,1H,Ar-H),7.295(s,2H,Ar-H),7.282(s,2H,Ar-H),7.269(s,2H,Ar-H),7.179(s,1H,Ar-H),7.16 7(s,1H,Ar-H),7.136(s,2H,Ar-H),7.123(s,2H,Ar-H),7.087(s,1H,Ar-H),7.075(s,1H,Ar-H),7 .063(s,1H,Ar-H),7.037(s,1H,Ar-H),7.023(s,1H,Ar-H),7.005(s,1H,CH),1.973-1.976(d,J=1 .8Hz,2H,CH),1.839-1.844(d,J=3.0Hz,1H,CH),1.794-1.797(d,J=1.8Hz,1H,CH),1.778-1.780( d,J=1.2Hz,1H,CH),1.755-1.761(d,J=3.6Hz,2H,CH),1.298(s,1H,CH),1.282(s,1H,CH),1.259( s,1H,CH),1.235(s,3H,CH),1.058(s,3H,CH),0.873(s,3H,CH),0.860(s,3H,CH).HRMS(ESI)m / z:C 54 H 51 N5, theoretical value: 769.41; measured value: 770.43 [M+H] + .

[0037] Performance Test:

[0038] (1) Energy level calculation of compounds

[0039] The electrochemical properties of the compound were tested by cyclic voltammetry (CV), and the oxidation / reduction onset potential of the compound was tested after calibration with ferrocene. The energy level and energy gap of the compound were calculated by UV spectroscopy and electrochemical tests.

[0040] The theoretical molecular conformations and molecular energy levels of the two compounds were studied using density functional theory (DFT) with Guassian 09 software and the B3LYP / 6-31G(d) basis set.

[0041] The results are shown in Table 1:

[0042] Table 1 Theoretical calculations of compounds

[0043]

[0044] an optically calculated value.

[0045] b DFT calculation values.

[0046] The electrochemical performance of the compounds was tested by cyclic voltammetry (CV). Figure 1 ), after calibration with ferrocene, the HOMO and LUMO energy levels (EHOMO / ELUMO) of compound 1 and compound 2 were calculated to be -3.97 / -0.95 eV and -4.50 / -1.84 eV, respectively (Equations 1, 2, and 3).

[0047] E g =1024 / λ onset eV (1)

[0048] HOMO=-[E oxonset -E(Fc / Fc + )+4.8]eV (2)

[0049] LUMO=HOMO+E g eV (3)

[0050] The HOMO / LUMO energy levels of compound 1 and compound 2 obtained by theoretical simulation are -3.61 / -1.25eV and -3.57 / -1.24eV, respectively. The energy levels calculated by DFT have similar trends to those calculated by CV. Theoretical calculations show that the dipole moments of compound 1 and compound 2 are 2.68debye and 3.22debye, respectively. The dipole moment of compound 2 is higher than that of compound 1. This may be because the TPA group in compound 2 enhances the ICT effect of the molecule, and strong ICT is more conducive to the charge transfer of the compound.

[0051] Density functional theory (DFT) was used to study the theoretical molecular conformations of the two compounds using the B3LYP / 6-31G(d) basis set. Figure 2As shown, the molecules of compound 1 and compound 2 present obvious twisted structures, and the dihedral angles between the phenyl and quinazoline rings of compound 1 and compound 2 are 39.91° and 36.15°, respectively.

[0052] Evaluation of the fluorescence properties of compounds

[0053] The fluorescence excitation of compounds 1 and 2 in solution, film and solid state was studied by fluorescence spectrometer. Figure 3 ) and emission spectra ( Figure 4 The compound was found to be -6 In the ethanol (EA) solution of 1% M, the fluorescence emission colors of the two compounds are different, green and blue respectively. In addition, in the solid and film states, the maximum fluorescence emission wavelength (λ max ) at 438 and 445 nm, respectively. Compound 2 exhibits blue-green fluorescence emission color in both solid and film states, λ max At 493 and 496nm respectively.

[0054] The AIE properties of the two compounds were tested using a fluorescence spectrometer. Figure 5 The AIE properties of the two molecules can be shown by their interaction in the EA / water mixture (f w ) to study the fluorescence emission spectrum. Figure 5 As shown in (a), in the EA / water mixed solvent, at an excitation wavelength of 383 nm, the compound 1 molecule exhibits typical AIE properties. As the water content increases, the solubility of the molecule in the EA / water mixed solution weakens, resulting in the aggregation of the compound 1 molecules, thereby enhancing the fluorescence emission intensity of the compound 1 molecules. w When f reaches 80%, the fluorescence emission intensity reaches the maximum value. This may be due to the aggregation of molecules to form nanoparticles as the water content increases. w When the concentration reaches 90%, the fluorescence emission intensity decreases significantly. This is because the molecules of compound 1 further aggregate in the mixed solvent containing a large amount of water, destroying the existence form of nanoparticles. Figure 5 As shown in (b), for compound 2 (λ ex =390nm), when f w When f is 0%, the fluorescence emission intensity of the compound molecule reaches the maximum value. w The fluorescence emission intensity decreases when f w It reaches the minimum when f is 50%. However, as the water content continues to increase, the fluorescence emission intensity of the molecule begins to increase. wWhen it reaches 60%, the maximum fluorescence emission wavelength of the molecule shifts to 430nm, and the fluorescence emission intensity of the molecule decreases. Compound 2 replaces the phenyl group in the molecular structure of compound 1 with a TPA group and exhibits strong fluorescence in the solution state. In addition, the large size and distorted structure of the molecular structure are not conducive to the formation of molecular nanoclusters.

[0055] Figure 5 (c) and (d) in FIG. 3 characterize the effect of temperature on the fluorescence emission of compound 1 and compound 2 molecules. Figure 5 (e) and (f) in the figure are CIE chromaticity diagrams of compound 1 and compound 2, which can more intuitively observe the change of the fluorescence emission color of the compound with temperature. The DMF dilute solution of compound 1 emits strong green fluorescence at 25°C ( Figure 5 (c) in Figure 1). After that, the fluorescence emission intensity gradually increased with the increase of temperature, while the maximum fluorescence emission wavelength slightly blue-shifted. The hydrophobic TPA groups in the compound molecules led to enhanced molecular aggregation, resulting in a gradual increase in fluorescence emission and a blue-shift.

[0056] However, the emission fluorescence of the DMF dilute solution of compound 2 is blue, and the fluorescence emission spectrum intensity reaches a maximum at 450nm at 25℃. As the temperature increases, the fluorescence emission intensity of the compound 2 molecule decreases slightly, and the maximum fluorescence emission wavelength shifts toward blue. The weak fluorescence emission at about 450nm can be attributed to the rotational relaxation of the phenyl group of the TPA unit at high temperature as the temperature increases, and the distortion of the molecular structure of compound 2 is not conducive to fluorescence emission. The phenomenon of fluorescence emission changing with temperature is reversible. The planar conformation has a higher potential energy than the distorted conformation, so the planar conformation of the molecule can promote the fluorescence emission of the molecule.

[0057] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. A person with ordinary knowledge in the technical field to which the present invention belongs may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the definition of the claims.

Claims

1. A use of a polynary nitrogen heterocyclic triphenylamine compound as an organic light-emitting material, characterized in that: The polynary nitrogen heterocyclic triphenylamine compound has the following structure: Wherein R is a phenyl group or a triphenylamine group.

2. The use according to claim 1, characterized in that The polynary nitrogen heterocyclic triphenylamine compound is used as a condensed light-emitting material.

3. The use according to claim 1, characterized in that The fluorescence emission color of the polynary nitrogen heterocyclic triphenylamine compound in a solution changes from green to blue as the temperature increases.

4. The use according to claim 1, characterized in that The applications include information storage, anti-counterfeiting, and sensor display.

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