Preparation method and application of dimeric azaperylene helical chiral luminescent molecule

Abstract

This invention belongs to the field of organic optoelectronic materials and specifically discloses a method for preparing the helical chiral luminescent molecule DNP-DA by dimerizing azaperylene (NP). This molecule has a twisted 1,6-diazacyclopyrimidine (DA) core skeleton, with conjugated high-luminescent azaperylenes at both ends, resulting in excellent chiral luminescence properties and supramolecular responsiveness. Through a simple synthetic process, the chiral luminescent molecule DNP-DA is obtained by dimerizing an azaperylene amino derivative in a single step. The DNP-DA preparation method provided by this invention is simple, easy to operate, and highly universal, allowing it to be applied to the construction of other chiral molecules. The product has broad application prospects in the field of organic circularly polarized optoelectronic materials.

Description

Technical Field

[0001] The invention relates to a preparation method and application of a helical chiral luminescent molecule DNP-DA obtained by dimerizing azaperylene, and belongs to the field of organic photoelectric materials. Background Art

[0002] Chirality has long fascinated researchers, but its application in functional materials was rarely explored until the discovery of circularly polarized luminescence (CPL). Circularly polarized luminescence, also known as chiral luminescence, not only holds significant research and application value in fields such as chiral recognition, spectroscopy, and information encoding, but has also garnered significant interest in other areas, including quantum computing, 3D displays, and bio-imaging. Currently, CPL-active materials are primarily developed through supramolecular strategies and the construction of chiral small molecules. While supramolecular approaches are effective in enhancing chiral optical properties, they suffer from the problem of dependence on external conditions. Therefore, the design and construction of chiral small molecules with stable, long-lasting CPL properties and well-defined structures is crucial. CPL-active materials are typically constructed by linking highly efficient chromophores to chiral substructures. Common chiral backbones include binaphthyls, helicenes, diphenylene cycloalkanes, bowl-shaped chiral molecules, and 1,2-diaminocyclohexanes. Furthermore, to address a wider range of circularly polarized optoelectronic applications, the development of novel CPL chiral substructures with high asymmetry factors and high chiral luminescence efficiency remains a hot topic for researchers in this field. The 1,6-diazacyclopyrimidine structure (abbreviated as DA, detailed structure shown below) is a bis-butadiene ten-membered ring structure bridged by two nitrogen atoms. This DA structure exhibits a twisted three-dimensional structure, promising axial chirality, making it a novel chiral substructure. Azoperylene (abbreviated as NP, detailed structure shown below) is a perylene bay conjugated to a pyrrole. It possesses abundant π electrons and excellent, tunable luminescence properties, and has been extensively studied in the fields of electron transport and luminescent materials. Therefore, in this invention, we combined 1,6-diazacyclopyrimidine (DA) with two highly efficient chromophores, azoperylene (NP), to create the novel, highly efficient chiral luminescent molecule DNP-DA.

[0003]

[0004] The present invention uses a simple synthesis process to dimerize the amino derivative 1 of the azaperylene (NP) molecule to obtain a new helical chiral luminescent molecule DNP-DA with a twisted 1,6-diazacyclopyrimidine (DA) structure as the core. This molecule has excellent absorption and emission asymmetry factors (g abs =1.5×10 -2 and g lum =6×10-3 ). And the asymmetric fluorescence emission of DNP-DA molecules is in the red region (610 nm), which is relatively rare in circularly polarized luminescent material molecules. In addition, due to its large curved electron-rich system, DNP-DA molecules have a strong affinity for fullerene C 60 The molecule exhibits a supramolecular response. In summary, the preparation method of the DNP-DA molecule provided by the present invention is simple and easy to operate; the DA group therein is highly universal and can be applied to the construction of other chiral molecules. Therefore, the product of the present invention has broad prospects for promotion and application in organic circularly polarized optoelectronic materials. Summary of the Invention

[0005] This invention designs and synthesizes a novel chiral fluorescent molecule, DNP-DA, based on a twisted DA structure at its core. This molecule belongs to the field of organic optoelectronic materials. Compound 1 is used as a raw material to obtain the target molecule, DNP-DA, through a transition metal-catalyzed CN coupling reaction in air. The synthesis reaction equation is as follows:

[0006]

[0007] The advantages of the present invention are: the synthesis method is simple and the reaction conditions are mild; the obtained product has excellent chiral photoelectric properties and supramolecular response properties; and this method has broad promotion and application prospects in organic photoelectric materials.

[0008] The synthesis process and conditions of the present invention are achieved by the following steps:

[0009] Palladium acetate, copper acetate, and compound 1 were added to a reaction tube in a certain mass ratio, and then toluene was added. The reaction mixture was stirred and refluxed at 120° C. for 12 hours. After the reaction, the reaction solution was filtered through diatomaceous earth, the filtrate was collected, and the solvent was recovered by vacuum distillation. A mixed solution of toluene, dichloromethane, and n-hexane in a volume ratio of 1:30:150 was used as an eluent, and separation and purification were performed using a silica gel chromatography column. The third orange-red band was collected to obtain a solution of compound DNP-DA. The solvent was recovered by vacuum distillation and vacuum drying to obtain a red solid substance, which is compound DNP-DA.

[0010] If the two enantiomers of the compound DNP-DA are to be further separated, chiral separation is required. The specific operation method is shown in the specific implementation method. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] 1. Figure 1 This is the H NMR spectrum of compound DNP-DA.

[0012] 2. Figure 2 This is the carbon NMR spectrum of the compound DNP-DA.

[0013] 3. Figure 3 This is the MALDI-TOF mass spectrum of compound DNP-DA.

[0014] 4. Figure 4 The UV-visible absorption spectra of compound DNP-DA in different solvents.

[0015] 5. Figure 5 Figure 2 is the fluorescence emission spectra of compound DNP-DA in different solvents.

[0016] 6. Figure 6 This is the circular dichroism absorption spectrum of compound DNP-DA in tetrahydrofuran.

[0017] 7. Figure 7 This is the absorption asymmetry factor diagram of compound DNP-DA calculated from the circular dichroism absorption spectrum test results.

[0018] 8. Figure 8 This is the circularly polarized emission spectrum of compound DNP-DA in tetrahydrofuran.

[0019] 9. Figure 9 This is the emission asymmetry factor diagram of compound DNP-DA calculated from the circularly polarized emission spectrum test results.

[0020] 10. Figure 10 C in toluene solution 60 UV-visible absorption spectrum of the titrated compound DNP-DA.

[0021] 11. Figure 11 C in toluene solution 60 Fluorescence emission spectrum of the titrated compound DNP-DA.

[0022] 12. Figure 12 The compound DNP-DA reacts with C in toluene solution. 60 Complexation constant fitting curve.

[0023] 13. Figure 13 HPLC chromatogram of the enantiomer separation of compound DNP-DA.

[0024] 14. Figure 14 This is the single crystal structure diagram of the compound DNP-DA. Implementation Method

[0025] Example 1. Synthesis of compound DNP-DA

[0026] To a 10-ml reaction tube equipped with a magnetic stirrer, 120 mg (0.142 mmol) of compound 1, 4 mg (0.016 mmol) of palladium acetate, 8 mg (0.040 mmol) of copper acetate, and 3 ml of toluene were added. The mixture was stirred and refluxed at 120°C for 12 hours. After completion of the reaction, the reaction solution was filtered through diatomaceous earth and eluted with dichloromethane until no fluorescent material was visible on the diatomaceous earth. The filtrates were combined and the solvent was recovered by vacuum distillation. Separation and purification were performed using silica gel column chromatography using a mixture of toluene, dichloromethane, and n-hexane (1:30:150 by volume) as the eluent. The third orange-red band was collected to obtain a solution of compound DNP-DA. The solvent was recovered by vacuum distillation and dried under vacuum to yield 6 mg of a red solid, DNP-DA, with a yield of 5%.

[0027] Example 2. Synthesis of compound DNP-DA

[0028] To a 10 ml reaction tube equipped with a magnetic stirrer, 120 mg (0.142 mmol) of compound 1, 7.2 mg (0.029 mmol) of palladium acetate, 34.2 mg (0.171 mmol) of copper acetate, and 3 ml of toluene were added. The mixture was stirred and refluxed at 120°C for 12 h. After the reaction, the reaction solution was filtered through diatomaceous earth and eluted with dichloromethane until no obvious fluorescence was observed on the diatomaceous earth. The filtrates were combined and the solvent was recovered by vacuum distillation. Separation and purification were performed by silica gel column chromatography using a mixture of toluene, dichloromethane, and n-hexane in a volume ratio of 1:30:150 as the eluent. The third orange-red band was collected to obtain a solution of compound DNP-DA. The solvent was recovered by vacuum distillation and dried in vacuo to obtain 10 mg of a red solid, compound DNP-DA, with a yield of 8.33%.

[0029] Example 3. Synthesis of compound DNP-DA

[0030] To a 10-ml reaction tube equipped with a magnetic stirrer, 60 mg (0.071 mmol) of compound 1, 7.2 mg (0.029 mmol) of palladium acetate, and 17.1 mg (0.086 mmol) of copper acetate were added, followed by 1.5 ml of toluene. The mixture was stirred and refluxed at 120°C for 12 h. After the reaction, the reaction solution was filtered through diatomaceous earth and eluted with dichloromethane until no fluorescent material was observed. The filtrates were combined and the solvent was recovered by vacuum distillation. Separation and purification were performed by silica gel column chromatography using a mixture of toluene, dichloromethane, and n-hexane in a volume ratio of 1:30:150 as the eluent. The third orange-red band was collected to obtain a solution of compound DNP-DA. The solvent was recovered by vacuum distillation and dried in vacuo to obtain 7.2 mg of a red solid, DNP-DA, with a yield of 12%.

[0031] H NMR spectrum of compound DNP-DA; 1 H NMR (500 MHz, Chloroform-d): δ (ppm)=8.02 (d, J = 9.1 Hz, 1H), 7.69 (s, 1H), 7.63 (s, H), 7.54 (d, J = 9.0 Hz,1H), 7.51 (dd, J = 9.0, 3.0 Hz, 1H), 7.07 (d, J = 9.0 Hz, 1H), 6.74 (dd, J =9.1, 3.0 Hz, 1H), 6.46 (d, J = 8.9 Hz, 1H), 6.15 (dd, J = 9.1, 3.0 Hz, 1H),5.46 (dd, J = 9.1, 3.0 Hz, 1H), 4.66 (t, J = 7.1 Hz, 2H), 3.76 (t, J = 6.6Hz, 2H), 2.10 (p, J = 7.3 Hz, 2H), 1.69 – 1.64 (m, 2H), 1.48 (dt, J = 12.4,6.3 Hz, 1H), 1.43 – 1.36 (m, 2H), 0.90 (t, J = 7.4 Hz, 3H), 0.86 (t, J= 7.4Hz, 4H).

[0032] Product structure characterization and performance research of this embodiment:

[0033] Single crystal cultivation method of compound DNP-DA

[0034] The method for growing single crystals of compound DNP-DA is slow diffusion method. The specific process is: 0.1 ml of dichlorobenzene solution of compound DNP-DA (concentration: 10 -2 M) was filtered through an organic microporous filter membrane (pore size 0.45 μm) and added to a smooth glass tube (inner diameter 4 mm, length 25 mm). This glass tube was placed in a sealed glass bottle (outer diameter 20 mm, height 80 mm; the glass tube mouth was above the methanol liquid level) containing 2 ml of methanol. The glass tube was placed at an angle in the small glass bottle at room temperature in a light-proof and vibration-proof environment. After 15 days of slow evaporation and diffusion, single crystals with regular morphology were obtained.

[0035] Separation of DNP-DA Enantiomers

[0036] Detailed process of chiral resolution of compound DNP-DA enantiomers: Compound DNP-DA was dissolved in chromatographically pure n-hexane at a concentration of 50 mg / ml and filtered using an organic microporous filter membrane (pore size 0.45 μm); the enantiomers were resolved using a preparative high performance liquid chromatograph and a chiral column Unichiral CND-5H; the mobile phase used was a mixed solution of diethanolamine, isopropanol, and n-hexane at a ratio of 1:10:990; two groups of resolved components were collected separately; the solvent was recovered by vacuum distillation to obtain a pure enantiomer product ( P )-DNP-DA and ( M )-DNP-DA, separation effect as attached Figure 13 shown.

[0037] Circular dichroism absorption spectra and circularly polarized luminescence properties of different enantiomers of the compound DNP-DA

[0038] The concentration used was 3×10 -5 M's ( P )-DNP-DA and ( M )-DNP-DA solution was tested; the circular dichroism absorption spectra of the two enantiomers were measured using a biologicmos 450 circular dichroism spectrometer, and the results are shown in the attached Figure 6 The circular polarization luminescence spectra of the two enantiomers were tested using a JASCOCPL-200 circular polarization spectrometer. The results are shown in the attached figure. Figure 8 As shown. ( P )-DNP-DA and ( M)-DNP-DA has a symmetrical circular dichroism spectrum with opposite Cotton effects, confirming their enantiomeric relationship; the two enantiomers show a perfect mirror relationship in the CPL spectrum, and the maximum asymmetric luminescence is at 600 nm; according to the absorption asymmetry factor calculation formula g abs =2( ε L - ε R ) / ( ε L + ε R )( ε L and ε R are the molar absorption coefficients of left-handed and right-handed polarized light, respectively), and the fluorescence asymmetry factor calculation formula g lum = 2(I L -I R ) / (I L +I R )(I L and I R The maximum absorption asymmetry factor of the compound DNP-DA in tetrahydrofuran solution is calculated to be g abs =1.5×10 -2 (430 nm), the fluorescence asymmetry factor is g lum =6×10 -3 The results are as follows Figure 7 and 9 The compound DNP-DA exhibits high asymmetry factors in both circular dichroism absorption and circularly polarized emission spectra, indicating that it has distinct chiral characteristics and has broad application potential in 3D display, chiral recognition, bioimaging, spectroscopy, and information coding.

[0039] Compound DNP-DA for fullerene C 60 Supramolecular response

[0040] Supramolecular response test process: The compound DNP-DA was dissolved in toluene and prepared to a concentration of 1.2×10 -5 M solution; Fullerene C 60 Dissolved in toluene to a concentration of 2.4×10 -3 M solution. Take 2 ml of 1.2×10 -5 The DNP-DA solution of the compound M was added to a cuvette with an optical path of 1 cm, and the emission spectrum of the DNP-DA solution was recorded at 450-800 nm with an excitation wavelength of 429 nm. Each time 5 equivalents of C 60solution (i.e. 50 μl of 2.4 × 10 -3 M's C 60 solution), shake well, and record the emission spectrum under the same conditions; repeat the above steps until C 60 A total of 200 equivalents were obtained. Figure 11 .

[0041] Supramolecular responsiveness: With the C 60 With the gradual addition of , the fluorescence signal of the compound DNP-DA was gradually quenched and split into three weak peaks until C 60 When the total amount reached 200 equivalents, the fluorescence signal was almost completely quenched. Figure 11 This shows that the compound DNP-DA and C 60 Host-guest interaction and charge transfer occurred. According to the fluorescence spectrum change line, the fluorescence intensity at 598 nm was taken as the independent variable, and the host-guest equivalent ratio [G]0 / [H]0 was taken as the dependent variable ([G]0 refers to C 60 The equivalent of [H]0 refers to the equivalent of the compound DNP-DA), the online calculation program BindFit was imported to obtain the fitting curve of this interaction, and the binding constant of this supramolecular (K a ) is 265 M −1 The results are as follows Figure 12 The above tests show that the compound DNP-DA, due to its dinitrogen atom structure at the DA center, the electron-rich nature of NP, and its curved molecular structure, endows it with supramolecular binding ability with receptor molecules, which will further expand the application of this product in chiral functional materials.

Claims

1. A dimeric azaperylene helical chiral luminescent molecule DNP-DA, characterized by: The dimeric azaperylene helical chiral luminescent molecule DNP-DA has the following molecular structure: With high asymmetry factor, absorption asymmetry factor g abs =1.5×10 -2 , fluorescence asymmetry factor g lum =6×10 -3 .

2. The method for preparing the dimeric azaperylene helical chiral luminescent molecule DNP-DA according to claim 1, characterized in that: Reaction process As shown below, the material ratio of the reaction is palladium acetate: copper acetate: compound 1 = 1: 2.375: 8.333 3. The method for preparing the dimeric azaperylene helical chiral luminescent molecule DNP-DA as claimed in claim 2, wherein: The reaction conditions were air environment, reaction temperature was 120° C., and reaction time was 12 hours.

4. The method for preparing the dimeric azaperylene helical chiral luminescent molecule DNP-DA as claimed in claim 2, wherein: The purification method is column chromatography, the adsorbent is neutral silica gel, and the eluent is a mixed solvent with a volume ratio of toluene: dichloromethane: n-hexane = 1:30:

150.

5. The method for preparing the dimeric azaperylene helical chiral luminescent molecule DNP-DA as claimed in claim 2, characterized in that: DNP-DA was subjected to helical chiral separation using preparative HPLC coupled with a chiral column UniChiralCND-5H, eluted with a mixed solvent of diethanolamine: isopropanol: n-hexane = 1:10:990 by volume, to obtain two helical chiral enantiomers as shown below:

6. Use of the dimeric azaperylene helical chiral luminescent molecule DNP-DA as claimed in claim 1 in the field of organic circularly polarized photoelectric materials.

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