Triaryl boron modified aza [7] helicene derivative with two-photon absorption and two-state circular polarization luminescence characteristics

Abstract

The invention relates to triaryl boron modified aza [7] helicene derivatives with two-photon absorption and two-state circular polarization luminescence characteristics. The invention belongs to the technical field of organic photoelectric functional materials, and provides an aza [7] helicene derivative with dual-state circular polarization luminescence and two-photon absorption properties. The fluorescent quantum efficiency of pure carbon [7] helicene is remarkably improved, and the double-state CPL and strong TPA characteristics are realized in a single organic molecule.

Description

Technical Field

[0001] This invention belongs to the field of organic optoelectronic functional materials technology, specifically involving azahexene derivatives that have both two-photon absorption and two-state circularly polarized light emission properties [7]. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Organic small molecule materials with circularly polarized light emission (CPL) properties have attracted considerable attention due to their wide range of applications in cutting-edge technologies such as 3D displays, information storage, high-security encryption, and bioimaging. The overall performance of CPL can be assessed by considering its brightness (…). B CPL = ε × Φ F × | g lum | / 2) This parameter is used for evaluation. In addition to pursuing high CPL brightness, achieving significant CPL signals in both solution and aggregated states (i.e., dual-state CPL) is also an important issue that urgently needs to be addressed. Dual-state CPL can resolve the contradiction between aggregation fluorescence quenching (ACQ) and aggregation-induced emission (AIE) effects, thereby ensuring that small organic molecule materials obtain stable CPL properties that are not affected by concentration.

[0004] On the other hand, in order to further expand the application range of molecules containing CPL characteristics, it is of great significance to combine two-photon absorption (TPA) characteristics with CPL organic small molecule systems. Molecules with two-photon absorption characteristics have unique advantages such as high three-dimensional spatial resolution, low photodamage, and large tissue penetration depth. Recently, the inventors used triarylborane units with strong electron withdrawal and large steric hindrance to obtain a nitrogen-containing [7]spiroene luminescent derivative with strong charge transfer state (CT). o BPh-NH-A7H; this molecule exhibits a high M value of 69.1 in solution. - ¹ cm - ¹CPL brightness ( B CPL ),That Φ F The value is 0.61. However, this donor (D)-acceptor (A) type molecule hardly exhibits two-photon absorption properties. Therefore, achieving dual-state CPL or CPL-TPA integration alone is already extremely challenging, and achieving both simultaneously is even more difficult. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a class of triarylboron-modified aza[7]helicene derivatives. Both compounds exhibit circularly polarized luminescence with high fluorescence quantum yield in solution, PMMA-doped films, and pure films. Furthermore, they also possess two-photon absorption properties, making them the first examples to simultaneously achieve dual-state circularly polarized luminescence and two-photon absorption performance.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a triarylboron-modified aza[7]helicene derivative exhibiting both two-photon absorption and two-state circularly polarized emission characteristics, wherein the structural formula is selected from one of the following formulas: .

[0007] In a second aspect, the present invention provides a method for preparing the above-mentioned aza[7]spiroene derivatives, using the following synthetic route (1) or (2): ; The route (1) is adopted, including: In an inert atmosphere, o Br-A7H, PdCl2(dppf), B2Pin2, and KOAc are mixed thoroughly, then 1,4-dioxane is added, and the mixture is heated to proceed with the reaction, yielding... o Bpin-A7H; Will o A mixture of Bpin-A7H, 4-Br-FBPh, Pd(PPh3)4, and K2CO3 was sequentially added to a redistilled and dried toluene solution, ethanol, and water, and the mixture was heated to proceed with the reaction, yielding... o FBPh-A7H; Alternatively, route (2) can be adopted, including: A7H was dissolved in chloroform, and N-bromosuccinimide was added to react and give oDiBr-A7H. Will o DiBr-A7H, PdCl2(dppf), B2Pin2, KOAc, and 1,4-dioxane were mixed thoroughly and then reacted. o BiBpin-A7H; Under the protection of an inert atmosphere, towards o A mixture of BiBpin-A7H, 4-Br-FBPh, Pd(PPh3)4, and K2CO3 was successively added to dried and degassed toluene, ethanol, and water, and the mixture was heated to proceed with the reaction, yielding... o BiFBPh-A7H.

[0008] A third aspect of the present invention provides the application of the above-mentioned aza[7]spiroene derivatives or aza[7]spiroene derivatives prepared by the above method in the fields of 3D display, optoelectronic information storage and processing, and biological probes.

[0009] A fourth aspect of the present invention provides the application of the above-described aza[7]helicene derivatives or aza[7]helicene derivatives prepared by the above method in the field of two-photon excitation and two-state CPL fluorescence imaging.

[0010] Beneficial effects of the present invention (1) Given that stronger charge transfer and multipolar molecular structures usually help to enhance two-photon absorption, this study designed two new types of triarylboron-modified aza[7]helicenes with dipole structures. o FBPh-A7H and Quadrupole Structure o BiFBPh-A7H. In these two compounds, the charge transfer properties of the molecules are further enhanced by introducing a 4-bis[2,6-bis(trifluoromethyl)phenyl]boronphenyl (FBPh) substituent, utilizing the significantly enhanced electron-withdrawing ability of 2,6-bis(trifluoromethyl)phenyl compared to mesitylene. The study found that the dipole structure... o FBPh-A7H exhibits significant two-photon absorption activity, with an absorption cross section ( δ TPA The value reaches 211 GM; while in the quadrupole structure o After introducing a second triarylboron branch into BiFBPh-A7H δ TPA The fluorescence quantum yield was further increased to 329 GM. Furthermore, due to their high fluorescence quantum yield in different states, these two compounds not only exhibit strong circularly polarized luminescence behavior in solution, but also show significant CPL signals in both PMMA-doped films and pure solid films, thus realizing that organic molecules simultaneously possess both highly efficient two-photon absorption activity and dual-state circularly polarized luminescence behavior.

[0011] (2) The preparation method of the present invention is simple, practical and easy to promote. Attached Figure Description

[0012] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. Exemplary embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0013] Figure 1 for o FBPh-A7H and o Synthetic route of BiFBPh-A7H; Figure 2 for o FBPh-A7H ando BiFBPh-A7H was used in different solvents (Cyclohexane, toluene, CHCl3, THF, all at a concentration of 1.0 × 10⁻⁶). –5 Fluorescence emission spectrum in M); Figure 3 (a) is o BPh-NH-A7H, o FBPh-A7H and o A comparison of the two-photon absorption (TPA) and double-wavelength single-photon absorption (OPA) spectra of BiFBPh-A7H in tetrahydrofuran (concentration 1.0 × 10⁻⁶). –5 M), and b) are the emission spectra of three compounds in tetrahydrofuran (concentration 1.0 × 10⁻⁶). –5 M, excitation wavelength is 380 nm); Figure 4 (a) is o Circular dichroism spectrum of FBPh-A7H in cyclohexane and solid state (top) and UV-Vis absorption spectrum (bottom) (concentration) c = 3.0 × 10 -5 M); (b) is o Circularly polarized emission spectra (top) and fluorescence spectra (bottom) of FBPh-A7H in cyclohexane and solid state (excitation wavelength 380 nm, concentration 3.0 × 10⁻⁶). -5 M); P -cyclohexane P -1% PMMA film P -neat film represents the curves of the P-configuration (dextral) in cyclohexane solution, the PMMA-doped film, and the thin film state, respectively. Similarly, M represents different states under the M-configuration (levorotatory). Figure 5 (a) is o Circular dichroism spectrum (top) and UV-Vis absorption spectrum (bottom) of BiFBPh-A7H in cyclohexane and solid state (concentration) c = 3.0 × 10 -5 M); (b) is o Circularly polarized emission spectra (top) and fluorescence spectra (bottom) of BiFBPh-A7H in cyclohexane and solid state (excitation wavelength 380 nm, concentration 3.0 × 10⁻⁶). -5 M); P -cyclohexane P -1% PMMA film, P -neat film represents the curves for the P configuration in cyclohexane solution, the PMMA-doped film, and the thin film state, respectively. Similarly, M represents different states under the M configuration; Figure 6 for o FBPh-A7H and o (a) Circular dichroism spectrum and (b) circularly polarized emission spectrum of BiFBPh-A7H in tetrahydrofuran; o FBPh-A7H, o Curves of the P and M configurations of BiFBPh-A7H in tetrahydrofuran; Figure 7 The 1H NMR spectrum of 4-Br-FBPh is shown. Figure 8 for o The proton NMR spectrum of Bpin-A7H; Figure 9 for o The proton NMR spectrum of FBPh-A7H; Figure 10 for o The proton NMR spectrum of DiBr-A7H; Figure 11 for o The proton NMR spectrum of BiBpin-A7H; Figure 12 for o The hydrogen NMR spectrum of BiFBPh-A7H. Detailed Implementation

[0014] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0015] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of skill in the art. The reagents and raw materials used in this invention are readily available through conventional means, and unless otherwise specified, they are used in accordance with conventional methods in the art or product instructions. Similarly, unless otherwise specified, the test methods of this invention are performed in accordance with conventional methods in the art or industry-standard methods or practices. Furthermore, any methods and materials similar to or equivalent to those described herein may be applied to the methods of this invention. The preferred embodiments and materials described herein are for illustrative purposes only.

[0016] This invention mainly proposes a triarylboron-modified aza[7]helicene derivative with both two-photon absorption and two-state circularly polarized emission characteristics, the structural formula of which is selected from one of the following formulas: .

[0017] The present invention also provides a method for preparing the above-mentioned aza[7]spiroene derivatives, using the following synthetic route (1) or (2): ; The route (1) is adopted, including: In an inert atmosphere, o Br-A7H, PdCl2(dppf), B2Pin2, and KOAc are mixed thoroughly, then 1,4-dioxane is added, and the mixture is heated to proceed with the reaction, yielding... o Bpin-A7H; Will o A mixture of Bpin-A7H, 4-Br-FBPh, Pd(PPh3)4, and K2CO3 was sequentially added to a redistilled and dried toluene solution, ethanol, and water, and the mixture was heated to proceed with the reaction, yielding... o FBPh-A7H; Alternatively, route (2) can be adopted, including: A7H was dissolved in chloroform, and N-bromosuccinimide was added to react the solution to obtain... o DiBr-A7H; Will o DiBr-A7H, PdCl2(dppf), B2Pin2, KOAc, and 1,4-dioxane were mixed thoroughly and then reacted. o BiBpin-A7H; Under the protection of an inert atmosphere, towards o A mixture of BiBpin-A7H, 4-Br-FBPh, Pd(PPh3)4, and K2CO3 was successively added to dried and degassed toluene, ethanol, and water, and the mixture was heated to proceed with the reaction, yielding... o BiFBPh-A7H.

[0018] o The amounts of Br-A7H, PdCl2(dppf), B2Pin2, and KOAc affect the efficiency of the synthesis reaction and o The purity of Bpin-A7H, therefore... o The molar ratios of Br-A7H, PdCl2(dppf), B2Pin2, and KOAc were studied, and preferably, the... o The molar ratio of Br-A7H, PdCl2(dppf), B2Pin2 and KOAc is 1.83-2:0.13-0.15:2.56-2.6:5.49-5.6 to obtain better reaction efficiency and purity.

[0019] o The amounts of Bpin-A7H, 4-Br-FBPh, Pd(PPh3)4, and K2CO3 will affecto The purity and yield of FBPh-A7H, therefore, this invention is for o The molar ratios of Bpin-A7H, 4-Br-FBPh, Pd(PPh3)4, and K2CO3 were investigated, and preferably, the... o The molar ratio of Bpin-A7H, 4-Br-FBPh, Pd(PPh3)4, and K2CO3 is 0.34-0.36 : 0.41-0.42 : 0.01-0.012 : 1.02-1.05 to improve... o Yield and purity of FBPh-A7H.

[0020] In order to improve the reaction efficiency of A7H and N-bromosuccinimide, the amount of A7H and N-bromosuccinimide used in this invention was studied. Preferably, the molar ratio of A7H and N-bromosuccinimide is 1:2-2.1 to obtain better reaction efficiency.

[0021] The amount of raw materials used will affect o The yield and purity of BiBpin-A7H, therefore, this invention is for o The molar ratio of DiBr-A7H, PdCl2(dppf), B2Pin2, and KOAc was studied, and preferably, the molar ratio of... o The molar ratio of DiBr-A7H, PdCl2(dppf), B2Pin2, and KOAc is 3.20-3.25:0.45-0.46:8.96-8.98:19.20-19.25 to improve... o Purity and yield of BiBpin-A7H.

[0022] o The amounts of BiBpin-A7H, 4-Br-FBPh, Pd(PPh3)4, and K2CO3 will affect o The synthesis efficiency and purity of BiFBPh-A7H are improved, therefore, this invention... o The molar ratios of BiBpin-A7H, 4-Br-FBPh, Pd(PPh3)4, and K2CO3 were investigated, and preferably, the... o The molar ratio of BiBpin-A7H, 4-Br-FBPh, Pd(PPh3)4 and K2CO3 is 0.28-0.30:0.67-0.68:0.02-0.03:1.68-1.69 to improve synthesis efficiency and purity.

[0023] This invention does not impose any particular limitation on the synthesis method of 4-Br-FBPh. Preferably, the synthesis method of 4-Br-FBPh includes: A solution of 2,6-bis(trifluoromethyl)bromobenzene in methyl tert-butyl ether and a solution of n-butyllithium in n-hexane are mixed evenly and reacted. After the reaction is complete, potassium (4-bromophenyl)trifluoroborate is added to the mixture, and the mixture is heated to obtain 4-Br-FBPh. More preferably, the molar ratio of 2,6-bis(trifluoromethyl)bromobenzene, n-butyllithium, and potassium (4-bromophenyl)trifluoroborate is 6.85-6.88:8.91-8.92:3.43-3.45 to obtain better synthesis efficiency and purity.

[0024] The present invention will be further described in detail below with reference to specific embodiments. It should be noted that the specific embodiments are explanations of the present invention and not limitations thereof.

[0025] In the following examples, melting point (Mp) was determined using a Tektronix XT-4 instrument. Proton (¹H) and carbon (¹³C) NMR spectra were recorded on a Bruker 400 NMR spectrometer, with chemical shifts based on CDCl3 (¹H NMR: δ = 7.26 ppm; ¹³C NMR: δ = 77.16 ppm). High-resolution mass spectrometry (HRMS) was performed using electrospray ionization time-of-flight mass spectrometry (ESI-TOF) on a Bruker Apex II mass spectrometer or a Thermal Orbitrap Exploris 120 mass spectrometer (APCI ion source). UV-Vis absorption and fluorescence spectra were measured using a Hitachi U-2910 spectrometer and a Hitachi F-7000 fluorescence spectrometer, respectively. Circular dichroism (CD) and circularly polarized emission (CPL) spectra were determined using an Applied Photophysics Chirascan spectrometer and a Jasco CPL 300 spectrometer, respectively. Transient fluorescence decay characteristics were measured using an Edinburgh Instrument FLS920 spectrometer. Two-photon absorption cross section was determined by two-photon excited fluorescence (TPEF) using coumarin 485 as a standard. TPEF emission, excitation, and other TPEF properties were recorded using a Coherent Mira 900 femtosecond Ti:sapphire laser as the pump source, coupled with a streak camera (Hamamatsu, model: C5680) and an imaging spectrometer (Hamamatsu, model: C5094). All reactions were performed under a nitrogen atmosphere. Potassium (4-bromophenyl)trifluoroborate, 11H-dibenzo[9,10-c:9',10'-g]carbazole (A7H) and 10-bromo-11H-dibenzo[9,10-c:9',10'-g]carbazole (A7H) o Br-A7H) were prepared according to the methods described in the literature. J. Am. Chem. Soc. 2013, 135 , 14012–14015. and Angew. Chem. Int. Ed. 2020, 59 , 7813–7817.) Example 1 The preparation method of the aza[7]spiroene derivatives of the present invention will be further described in detail below with reference to specific embodiments. It should be noted that the specific embodiments are for the purpose of explaining the present invention rather than limiting it.

[0026]

[0027] Synthesis of compound 4-bromo-bis[2,6-bis(trifluoromethyl)phenyl]boronylbenzene (4-Br-FBPh): To a solution of 2,6-bis(trifluoromethyl)bromobenzene (2.00 g, 6.85 mmol) in methyl tert-butyl ether (MTBE, 30 mL), a solution of n-butyllithium in n-hexane (3.56 mL, 2.5 M, 8.91 mmol) was slowly added dropwise via syringe at –78 ºC. The mixture was stirred at room temperature for 2.5 h. Subsequently, potassium (4-bromophenyl)trifluoroborate (900 mg, 3.43 mmol) was added to the mixture. The mixture was stirred at 65 ºC for 12 h. The reaction was quenched with water, then extracted with dichloromethane and water. The resulting organic phase was dried over anhydrous Na₂SO₄, filtered, and concentrated under reduced pressure. The solution was then analyzed by silica gel column chromatography (pure petroleum ether, R…). f Purification was performed using a concentration of 0.65 μL to give 910 mg (1.54 mmol) of 4-Br-FBPh as a pale white solid, with a yield of 45%. Mp 129.0–130.1 ºC; 1 H NMR (400 MHz, CDCl3) δ 7.96 (d, J = 8.0 Hz, 4H), 7.76 (t, J = 8.0 Hz, 2H), 7.46 (d, J = 8.4 Hz, 2H), 7.05 (d, J = 8.4 Hz, 2H). 13 C NMR (100 MHz, CDCl3) δ137.8, 130.8, 130.6, 130.2, 128.5, 128.0, 125.3, 122.5, 119.8. HRMS (APCI) m / z: [M] + Calcd for C 22 H 10 BBrF12 : 591.9867; Found 591.9862. The target compound is 10-(4,4,5,5-tetramethyl-1,3,2-dioxaborphane-2-yl)-11H-dibenzo[9,10-c:9',10'-g]carbazole ( o Synthesis of Bpin-A7H): In a nitrogen atmosphere, towards o 1,4-Dioxane (15 mL) was added to a mixture of Br-A7H (1.00 g, 1.83 mmol), PdCl2 (dppf) (93.73 mg, 0.13 mmol), pinacol diboronate (B2Pin2, 0.65 g, 2.56 mmol), and potassium acetate (KOAc, 0.54 g, 5.49 mmol). The mixture was stirred at 110 °C for 12 hours. The reaction system was slowly cooled to room temperature, and 1,4-Dioxane was removed by concentration under reduced pressure. The resulting mixture was analyzed by silica gel column chromatography (petroleum ether / dichloromethane = 1:1, R... f Purification (= 0.60) yielded 0.76 g (1.28 mmol). o Bpin-A7H is a yellow solid with a yield of 70%. Mp 228.5–229.7 ºC; 1 H NMR (400 MHz, CDCl3) δ 10.16 (s, 1H), 9.29 (s, 1H), 8.90 (d, J = 7.6 Hz, 1H), 8.84 (d, J = 8.8 Hz, 1H), 8.77 (d, J = 8.0 Hz, 1H), 8.72–8.68 (m, 2H), 8.44 (d, J = 8.0 Hz, 1H), 8.43 (d, J = 7.2 Hz, 1H), 8.02 (d, J = 8.8Hz, 1H), 7.81–7.65 (m, 6H), 7.23 (t, J = 7.2 Hz, 1H), 7.21 (t, J = 7.2 Hz, 1H), 6.36 (t, J = 7.2 Hz, 1H), 6.34 (t, J = 7.2 Hz, 1H), 1.58 (s, 6H), 1.57 (s, 6H) 13CNMR (100 MHz, CDCl3) δ 144.5, 139.5, 131.1, 131.0, 130.7, 130.61, 130.59,129.33, 129.25, 129.1, 128.53, 128.52, 128.2, 127.8, 127.4, 127.22, 127.15,126.8, 125.93, 125.86, 124.61, 124.58, 124.0, 123.7, 123.6, 123.4, 123.2,121.83, 121.82, 121.4, 118.2, 117.7, 111.6, 84.6, 25.3. HRMS (ESI) m / z: [M+H] + Calcd for C 42 H 33 BNO2: 594.2599; Found 594.2605. The target compound is 10-{4-bis[2,6-bis(trifluoromethyl)phenyl]boron}phenyl-11H-dibenzo[9,10-c:9',10'-g]carbazole ( o Synthesis of FBPh-A7H): In a nitrogen atmosphere o A mixture of Bpin-A7H (0.20 g, 0.34 mmol), 4-Br-FBPh (0.24 g, 0.41 mmol), tetrakis(triphenylphosphine)palladium (Pd(PPh3)4, 11.79 mg, 0.01 mmol), and K2CO3 (0.14 g, 1.02 mmol) was sequentially supplemented with redistilled toluene solution (16 mL), ethanol (8 mL), and water (8 mL). The mixture was stirred in an oil bath at 110 °C for 5 minutes. After the reaction solution cooled to room temperature, it was extracted with dichloromethane. The organic phase was dried over anhydrous Na2SO4, filtered, and concentrated under reduced pressure. The crude product was analyzed by silica gel column chromatography (petroleum ether / dichloromethane = 4:1, R... f = 0.46) for initial purification, followed by silica gel column chromatography (petroleum ether / ethyl acetate = 40:1, R f Purification was performed at 0.40 g to obtain 0.10 g (0.1 mmol) of the target product. o FBPh-A7H is a yellow solid with a yield of 30%. Mp 256.5–257.8 ºC; 1 HNMR (400 MHz, CDCl3) δ 9.01 (s, 1H), 8.85–8.79 (m, 3H), 8.75 (d,J = 8.4 Hz, 1H), 8.72 (d, J = 8.0 Hz, 2H), 8.45 (d, J = 8.0 Hz, 2H), 8.06 (d, J = 8.0 Hz, 4H) ,7.95–7.89 (m, 3H), 7.86–7.80 (m, 4H), 7.74 (t, J = 7.2 Hz, 2H), 7.68 (t, J = 8.0Hz, 2H), 7.54 (d, J = 8.0 Hz, 2H), 7.23 (t, J = 7.2 Hz, 2H), 6.38 (t, J = 7.6 Hz, 2H). 13 C NMR (100 MHz, CDCl3) δ 143.2, 139.5, 139.0, 137.9, 137.4, 130.9,130.8, 130.7, 130.6, 130.5, 130.3, 129.6, 129.4, 128.7, 128.6, 128.1, 127.9,127.6, 127.3, 127.2, 127.1, 127.0, 126.2, 126.0, 125.5, 124.8, 124.74,124.68, 124.6, 124.4, 123.8, 123.7, 123.40, 123.37, 122.7, 121.92, 121.88,121.8, 121.4, 119.3, 118.9, 111.5. HRMS (ESI) m / z: [M+H] + Calcd for C 58 H 31 BF 12 N:980.2352; Found 980.2365. Compound 10,12-dibromo-11H-dibenzo[9,10-c:9',10'-g]carbazole ( o Synthesis of DiBr-A7H): A7H (1 g, 2.14 mmol) was dissolved in chloroform (40 mL) and stirred at 0 ºC for 10 minutes. Then, N-bromosuccinimide (0.76 mg, 4.28 mmol) was slowly added to the solution, and the mixture was stirred at 0 ºC for 30 minutes. The solvent was then removed by rotary evaporation under reduced pressure. The resulting mixture was analyzed by silica gel column chromatography (petroleum ether / dichloromethane = 4:1, R...). f = 0.69) purified to give 0.74 g (1.18 mmol) oDiBr-A7H as a pale yellow solid, yield 55%. Mp 286.4–288.7 ºC; 1 H NMR (400MHz, CDCl3) δ 9.23 (s, 1H), 8.99 (s, 2H), 8.70 (d, J = 8.4 Hz, 2H), 8.67 (d, J =8.4 Hz, 2H) 8.43 (d, J = 8.0 Hz, 2H), 7.76 (t, J = 6.8 Hz, 2H), 7.71 (t, J = 8.0Hz, 2H), 7.63 (d, J = 8.0 Hz, 2H), 7.23 (t, J = 8.0 Hz, 2H), 6.33 (t, J = 7.2 Hz, 2H). HRMS (ESI) m / z: [M] + Calcd for C 36 H 19 Br2N: 622.9884; Found 622.9862.

[0028] Compound 10,12-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborhecyclopentan-2-yl)-11H-dibenzo[9,10-c:9',10'-g]carbazole ( o Synthesis of BiBpin-A7H): The preparation of this compound is basically in accordance with the above. o The method described in Bpin-A7H is used. oDiBr-A7H (2.00 g, 3.20 mmol), PdCl2(dppf) (0.33 g, 0.45 mmol), B2Pin2 (2.27 g, 8.96 mmol), KOAc (1.88 g, 19.20 mmol), and 1,4-dioxane (25 mL) were reacted. The crude product was analyzed by silica gel column chromatography (petroleum ether / dichloromethane = 3:1, R... f = 0.32) Purification yielded 1.50 g (2.08 mmol) o BiBpin-A7H is a yellow solid with a yield of 65%. Mp 358.5–360.4 ºC; 1 H NMR (400 MHz, CDCl3) δ 11.17 (s, 1H), 9.33 (s, 2H), 8.94 (d, J = 8.0 Hz, 2H), 8.71 (d, J = 8.0 Hz, 2H), 8.45 (d, J = 8.0 Hz, 2H), 7.84(d, J = 8.0 Hz, 2H), 7.76 (t, J = 7.2 Hz, 2H), 7.68 (t, J = 7.2 Hz, 2H), 7.24 (t, J =7.2 Hz, 2H), 6.38 (t, J = 7.6 Hz, 2H), 1.61 (s, 12H), 1.60 (s, 12H). 13 C NMR (100MHz, CDCl3) δ 144.3, 131.1, 130.6, 130.5, 129.3, 129.2, 129.1, 128.5, 127.3,127.2, 125.8, 124.6, 124.0, 123.4, 123.2, 121.8, 117.3, 110.1, 84.4, 25.4.HRMS (ESI) m / z: [M+H] + Calcd for C 48 H 44 B2NO4: 720.3451; Found 720.3462. The target product is 10,12-bis{4-bis[2,6-bis(trifluoromethyl)phenyl]boronphenyl}-11H-dibenzo[9,10-c:9',10'-g]carbazole ( oSynthesis of BiFBPh-A7H): The preparation of this compound is basically in accordance with the above. o The method described in FBPh-A7H is performed. Under nitrogen protection, [the process is carried out] towards... o A mixture of BiBpin-A7H (0.20 g, 0.28 mmol), 4-Br-FBPh (0.40 g, 0.67 mmol), Pd(PPh3)4 (19.41 mg, 0.02 mmol), and K2CO3 (0.23 g, 1.68 mmol) was sequentially supplemented with dried and degassed toluene (16 mL), ethanol (8 mL), and water (8 mL). The mixture was stirred in an oil bath at 110 ºC for 7 minutes. The crude product was analyzed by silica gel column chromatography (petroleum ether: dichloromethane = 2:1, R... f = 0.28) for initial purification, followed by silica gel column chromatography (petroleum ether:ethyl acetate = 40:1, R f Purification at 0.35 g yielded 0.11 g (0.07 mmol) of the target product. o BiFBPh-A7H, a yellow solid, in yield of 26%. Mp 282.6–283.6 o C; 1 H NMR (400 MHz, CDCl3) δ 9.41 (s, 1H), 8.84 (s, 2H), 8.81 (d, J = 8.0 Hz, 2H), 8.72 (d, J = 7.6 Hz, 2H), 8.44 (d, J = 8.0 Hz, 2H), 8.01 (d, J = 8.0 Hz, 8H), 7.90–7.83 (m, 6H), 7.82–7.72 (m, 6H), 7.69 (t, J =7.6 Hz, 2H), 7.46 (d, J = 7.6 Hz, 4H), 7.23 (t, J = 7.6 Hz, 2H), 6.40 (t, J = 7.6Hz, 2H). 13C NMR (100 MHz, CDCl3) δ 143.0, 138.9, 137.9, 137.2, 130.7, 130.6,130.4, 130.2, 129.6, 128.7, 128.0, 127.6, 127.3, 127.13, 127.05, 126.3,125.4, 124.8, 123.8, 123.4, 122.7, 122.0, 119.9, 119.5. HRMS (ESI) m / z: [M+H] + Calcd for C 80 H 40 B2F 24 N: 1492.2958; Found 1492.2954. Example 2 Optical properties of the target product: The UV-Vis absorption and fluorescence spectra of FBPh-substituted aza[7]helicenes in cyclohexane are as follows: Figure 3 As shown. In the absorption spectrum, mono-FBPh-substituted aza[7]helicene o FBPh-A7H exhibits the longest absorption bands at 327 nm and 437 nm, with very high intensity (the molar absorptivity at the strongest and longest wavelengths are respectively...). ε = 11.5 × 10 4 M -1 cm -1 3.10 × 10 4 M -1 cm -1 ). o FBPh-A7H emits blue-green fluorescence and exhibits a good fluorescence quantum efficiency (0.56). Notably, compared to previously reported BPh-substituted... o Compared to BPh-NH-A7H, o Both the longest wavelength absorption band and emission peak of FBPh-A7H exhibit a significant redshift (absorption redshift Δ). λ = 14 nm, emission redshift Δ λ = 36 nm). Furthermore... o The solvation effect of FBPh-A7H is more significant. Figure 2 When the solvent was changed from cyclohexane to THF, the concentration remained at 1.0 × 10⁻⁶. –5 At time M, o The emission peak of FBPh-A7H is redshifted by 57 nm, while o The fluorescence of BPh-NH-A7H is only redshifted by 22 nm. Because... oFBPh-A7H exhibits a strong solvation effect, emitting a yellow luminescence in polar THF and possessing moderate... Φ F (0.15). Relative to o BPh-NH-A7H, o The redshift in absorption and emission, as well as the stronger solvation phenomenon, of FBPh-A7H can be attributed to the stronger electron-withdrawing ability of the bis[2,6-bis(trifluoromethyl)phenyl]boron group compared to the xylylboron group, thus giving its first excited state (S1) stronger charge transfer (CT) characteristics. This is due to the substitution of single FBPh... o FBPh-A7H to Dual FBPh Replacement o BiFBPh-A7H exhibits a further significant enhancement in absorbance. Its strongest and longest wavelength absorption bands... ε Each is as high as 15.6 × 10 4 M -1 cm -1 and 5.75 × 10 4 M - 1 cm -1 .

[0029] Table 1. o FBPh-A7H and o Summary table of photophysical properties of BiFBPh-A7H

[0030] Example 3 Two-photon absorption properties of the target compound: exist o FBPh-A7H enhances charge transfer properties and o Fueled by the quadrupole structure characteristics of BiFBPh-A7H, this invention further investigated the two-photon absorption properties of these two compounds. In THF solution (concentration 1.0 × 10⁻⁶), –5 In M), two-photon excitation fluorescence was used, with coumarin 485 as the standard, at 720 Their two-photon absorption spectra were measured using femtosecond laser excitation in the 1000 nm wavelength range. Figure 3 (a). Notably, both compounds exhibit strong two-photon absorption responses, indicating their efficient nonlinear optical behavior. o The maximum two-photon absorption cross section of FBPh-A7H at 780 nm ( δ TPA The concentration was measured to be 211 GM. (Compared to...) o Compared to FBPh-A7H, oBiFBPh-A7H δTPA An increase of 117 GM was achieved, reaching 329 GM at 750 nm. From o FBPh-A7H to o BiFBPh-A7H, δ TPA The significant enhancement clearly highlights that the quadrupole system is superior to the dipole structure in amplifying the two-photon absorption intensity.

[0031] Example 4 The method for preparing PMMA-doped thin films is as follows: A chloroform solution of 99 mg PMMA is heated to 60°C, and 1 mg... o FBPh-A7H and o The chloroform solution of BiFBPh-A7H was added to the above PMMA solution, and after mixing evenly, an appropriate amount of solution was dropped onto a quartz plate. After the solution returned to room temperature, it formed a film for later use.

[0032] The powder state is o FBPh-A7H and o BiFBPh-A7H crystalline non-disturbing powder; Thin film is a compound o FBPh-A7H and o BiFBPh-A7H powder was dissolved in dichloromethane solvent and then dropped onto a quartz plate. After the solvent evaporated, a film was formed.

[0033] Solid-state properties of the target compound: As shown in Table 1, regarding o FBPh-A7H and o Another noteworthy characteristic of the photophysical properties of BiFBPh-A7H is that they all exhibit strong fluorescence emission in the solid state, whether in polymethyl methacrylate (PMMA) doped films or in aggregated states in powder and pure films. For PMMA doped films (1% wt), their absorption and fluorescence spectra are highly similar to those in cyclohexane solution, and the fluorescence quantum efficiency (QQ) is also high. Φ F The efficiency of both compounds approaches 1. The significant increase in efficiency from cyclohexane solution to PMMA-doped films is mainly attributed to the suppression of molecular vibrations, which can be explained by the substantial reduction in the nonradiative decay rate constant. Notably, the efficiencies of both compounds in pure films and powders (0.59–0.82) are even higher than their values ​​in cyclohexane solution. Specifically, o The pure thin film efficiency of FBPh-A7H can reach 0.77. oBiFBPh-A7H reached 0.82. Fluorescence kinetics studies showed that the efficiency improvement from cyclohexane solution to pure film was mainly attributed to the suppression of non-radiative decay processes. The emission spectra of powder and pure film were similar to those in THF solution. Therefore, the two compounds can exhibit different emission colors in dispersed and aggregated solid states: PMMA-doped film exhibits blue-green fluorescence, while pure film and powder exhibit yellow fluorescence, thus achieving two bright solid-state fluorescence colors. These FBPh-substituted aza[7]helicenes exhibit high molar extinction coefficients in all states ( ε ) and high fluorescence quantum yield ( Φ F This fully demonstrates its excellent luminescent properties.

[0034] Example 5 Study on the chiral optical properties of the target compound: like Figure 4 , 5 As shown in Figures 6 and 7, the chiral optical properties of these compounds in different states were systematically characterized, including nonpolar cyclohexane and THF solutions, PMMA-doped films, and pure films. In circular dichroism spectroscopy, both compounds exhibited a near-perfect mirror-symmetric Cotton effect in all tested states. More importantly, a clear mirror-symmetric signal was also observed in circularly polarized emission spectroscopy. Their emission asymmetry factor | g lum |for 10 -3 Order of magnitude (0.97–1.58 × 10⁻⁶) -3 This is comparable to the values ​​of common small organic molecules. Because... o The molar extinction coefficient of BiFBPh-A7H ( ε The CPL brightness is higher than that of oFBPh-A7H. B CPL The concentration is also higher in cyclohexane solution. o BiFBPh-A7H B CPL Up to 56.4 M -1 cm -1 These values ​​are remarkable for small organic molecules. More importantly, both compounds exhibit significant CPL mirror symmetry, high fluorescence quantum yield, and bright emission colors in both PMMA and pure films, demonstrating their enormous application potential in solid-state applications and dual-state circularly polarized luminescence behavior.

[0035] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A triarylboron-modified aza[7]helicene derivative exhibiting both two-photon absorption and two-state circularly polarized luminescence characteristics, characterized in that, The structural formula is selected from one of the following: 。 2. The method for preparing aza[7]spiroene derivatives as described in claim 1, characterized in that, The following synthetic routes (1) or (2) are adopted: ； The route (1) is adopted, including: In an inert atmosphere, o Br-A7H, PdCl2(dppf), B2Pin2, and KOAc are mixed thoroughly, then 1,4-dioxane is added, and the mixture is heated to proceed with the reaction, yielding... o Bpin-A7H; Will o A mixture of Bpin-A7H, 4-Br-FBPh, Pd(PPh3)4, and K2CO3 was sequentially added to a redistilled and dried toluene solution, ethanol, and water, and the mixture was heated to proceed with the reaction, yielding... o FBPh-A7H; Alternatively, route (2) can be adopted, including: A7H was dissolved in chloroform, and N-bromosuccinimide was added to react and give oDiBr-A7H. Will o DiBr-A7H, PdCl2(dppf), B2Pin2, KOAc, and 1,4-dioxane were mixed thoroughly and then reacted. o BiBpin-A7H; Under the protection of an inert atmosphere, towards o A mixture of BiBpin-A7H, 4-Br-FBPh, Pd(PPh3)4, and K2CO3 was successively added to dried and degassed toluene, ethanol, and water, and the mixture was heated to proceed with the reaction, yielding... o BiFBPh-A7H.

3. The method for preparing aza[7]spiroene derivatives as described in claim 2, characterized in that, The o The molar ratio of Br-A7H, PdCl2(dppf), B2Pin2 and KOAc is 1.83-2:0.13-0.15:2.56-2.6:5.49-5.

6.

4. The method for preparing aza[7]spiroene derivatives as described in claim 2, characterized in that, The o The molar ratio of Bpin-A7H, 4-Br-FBPh, Pd(PPh3)4 and K2CO3 is 0.34-0.36: 0.41-0.42: 0.01-0.012: 1.02-1.

05.

5. The method for preparing aza[7]spiroene derivatives as described in claim 2, characterized in that, The molar ratio of A7H and N-bromosuccinimide is 1:2-2.

1.

6. The method for preparing the aza[7]spiroene derivative according to claim 2, characterized in that, The molar ratio of iBr-A7H, PdCl2(dppf), B2Pin2, and KOAc is 3.20-3.25: 0.45-0.46: 8.96-8.98: 19.20-19.

25.

7. The method for preparing the aza[7]spiroene derivative according to claim 2, characterized in that, The o The molar ratio of BiBpin-A7H, 4-Br-FBPh, Pd(PPh3)4 and K2CO3 is 0.28-0.30: 0.67-0.68: 0.02-0.03: 1.68-1.

69.

8. The method for preparing aza[7]spiroene derivatives as described in claim 2, characterized in that, The synthesis method of the 4-Br-FBPh includes: A solution of 2,6-bis(trifluoromethyl)bromobenzene in methyl tert-butyl ether was mixed with a solution of n-butyllithium in n-hexane and the mixture was reacted. After the reaction was completed, potassium (4-bromophenyl)trifluoroborate was added to the mixture and the mixture was heated to give 4-Br-FBPh. Alternatively, the molar ratio of 2,6-bis(trifluoromethyl)bromobenzene, n-butyllithium, and potassium (4-bromophenyl)trifluoroborate is 6.85-6.88:8.91-8.92:3.43-3.

45.

9. The application of the aza[7]spiroene derivatives of claim 1 or the aza[7]spiroene derivatives prepared by the method of any one of claims 2-8 in the fields of 3D display, optoelectronic information storage and processing and biological probes.

10. The application of the aza[7]helicene derivative of claim 1 or the aza[7]helicene derivative prepared by the method of any one of claims 2-8 in the field of two-photon excitation and two-state CPL fluorescence imaging.

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