Self-assembly method based on triazine-carborane chiral material

Abstract

The invention relates to the technical field of chiral self-assembly materials, and discloses a novel achiral fluorescent material which is characterized in that a D-A type conjugated skeleton is constructed by taking a spirofluorene unit as an electron donor (D) and carborane and triazine as electron acceptors (A); carborane has an AIE effect, triazine is an important six-membered heteroaromatic ring, has three nitrogen atoms, generates three regioisomers, and is widely used for preparing thermal delay fluorescent materials due to good thermal stability, light stability and thermal delay performance; a triazine derivative is used as a hub to be respectively connected with spirofluorene-o-carborane; a three-dimensional space structure of an o-carborane molecule and a rigid structure of a triazine molecule are combined, so that unique photoelectric properties are achieved; the invention provides a basis for the design of the boron cluster material in the aspects of photoelectric application and the like; and a new thought is provided for the research of the light-emitting boron cluster in circularly polarized light emission.

Description

Technical Field

[0001] This invention relates to the field of chiral self-assembly materials technology, specifically to a chiral self-assembly material based on triazine-carborane and its self-assembly method. Background Technology

[0002] Supramolecular chemistry constructs dynamic functional molecular systems by regulating non-covalent intermolecular interactions such as hydrogen bonds, π-π stacking, and electrostatic interactions, revealing the chemical mechanism underlying the spontaneous self-organization of molecules into ordered structures. This research field achieves deep interdisciplinary integration with chiral materials research, which, as a cutting-edge research topic spanning chemistry, physics, biology, and nanoscience, possesses unique academic value and application potential at the molecular and supramolecular scales. Chirality is not only a core structural feature of living systems but also has core application value in drug molecule design and functional material development—molecular chirality directly governs the bioactivity and in vivo metabolic processes of drugs, while supramolecular chiral transfer provides a novel technological paradigm for the construction of dynamically responsive materials. In recent years, self-assembly strategies based on supramolecular chemistry principles have become a core technological path for the development of chiral nanomaterials. Researchers can precisely regulate non-covalent interactions such as hydrogen bonds, π-π stacking, ion-dipole interactions, electrostatic interactions, acid-base interactions, and van der Waals forces to directionally construct nanoscale or microscale supramolecular systems with specific functions. The reversible nature of such weak interactions endows materials with dynamic response properties. For example, external field stimuli such as temperature control and solvent polarity adjustment can induce structural reorganization in materials, thereby enabling real-time dynamic control of the material's microstructure and application functions.

[0003] In the development and fabrication of high-performance circularly polarized luminescence (CPL) active materials, supramolecular self-assembly systems have become a core research hotspot. Precisely controlling the arrangement of structural units through self-assembly strategies can significantly improve the optical properties of materials. For example, embedding inorganic materials into a chiral supramolecular matrix can impart CPL activity through non-covalent interactions, eliminating the need for complex chiral modifications. This type of co-assembly system effectively simplifies the cumbersome preparation process of traditional synthesis and provides a new technical pathway for flexibly controlling the chiral sign and emission wavelength of the CPL signal. Researchers can directionally optimize the emission asymmetry factor and quantum efficiency of materials by adjusting the proportions of components in the assembly system and controlling the interaction types.

[0004] Both supramolecular organic and inorganic materials can be embedded into chiral host systems to prepare a series of CPL active materials, laying the foundation for the large-scale research and application of CPL materials.

[0005] Carboranes are a class of polyhedral clusters composed of carbon and boron atoms, characterized by their terminal boron atoms. These terminal boron atoms can be replaced by carbon atoms, resulting in various types of carboranes. As the number of substituted boron and hydrogen atoms increases, carboranes can form clusters of various sizes and shapes, with diverse arrangement patterns. Based on their structure, carborane compounds can be classified into three categories: closed (closo), open (nido), and arachnoid. Due to their three-dimensional aromaticity and icosahedral cage structure, carboranes are often used in the preparation of polymer materials to extend conjugated chains and impart unique photoelectric properties. By introducing different functional groups to prepare different carborane derivatives, the vibrational characteristics of the C-C bonds in the molecule can be altered, thereby modulating the luminescent properties of photoelectric materials. Because the electronegativity of boron atoms (2.04) is lower than that of hydrogen atoms (2.20), they can form a richer variety of weakly interacting bonds, such as Bδ+-Hδ-…Hδ+-Cδ-, Bδ+-Hδ…M+, and Bδ+-Hδ-…π. This is the driving force for self-assembly, thus eliminating redundant organic synthesis steps. Chiral small molecules are connected to non-chiral luminescent materials through interaction forces to prepare multi-level chiral organic supramolecular aggregates, generating and improving circularly polarized luminescence performance. Currently, various carborane-containing luminescent materials have been developed, covering a variety of colors including green, blue, yellow, and white light. These materials can be widely used in the field of organic light-emitting diodes (OLEDs). In addition to their applications in polymer materials, carboranes are also widely used in optoelectronic switches, optical information processing, and laser frequency conversion.

[0006] Designing achiral carborane derivative luminescent materials and conducting self-assembly studies with chiral small molecules can avoid lengthy chiral material synthesis processes, while simultaneously improving the CPL and g of the products. lum The value is elevated to a higher level, but there is currently limited research on the chirality of carborane-based luminescent materials, and the reported boron cluster materials g lum The CPL (Chip-Plastic Producing) value is relatively low, and the assembly method is relatively simple. To address this issue, this invention focuses on developing novel boron cluster luminescent materials and designing new self-assembly schemes based on the material's characteristics to improve its CPL performance. Summary of the Invention

[0007] The purpose of this invention is to provide a chiral self-assembly material and method based on triazine-carborane materials to solve the problems mentioned in the background art.

[0008] This invention discloses a novel achiral fluorescent material, constructing a DA-type conjugated framework using spirofluorene units as electron donors (D) and carborane and triazine as electron acceptors (A). Carborane exhibits the AIE effect, while triazine is an important class of six-membered aromatic heterocycles with three nitrogen atoms, producing three regioisomers. Due to its excellent thermal stability, photostability, and thermal delay properties, it is widely used in the preparation of thermally delayed fluorescent materials. Spirofluorene and o-carborane are linked by triazine derivatives as hubs. Combining the three-dimensional spatial structure of the o-carborane molecule with the rigid structure of the triazine molecule results in unique photoelectric properties.

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] This invention provides a triazine-carborane material, the structure of which is shown in Formula C1:

[0011] Formula C1.

[0012] This invention also provides a method for preparing a triazine-carborane material, the process flow of which is as follows:

[0013] ; .

[0014] Furthermore, the preparation method specifically includes the following steps:

[0015] (1) Synthesis of intermediate 2: Decaborane was placed in a reactor, and nitrogen was purged three times. N,N-dimethylaniline was dissolved in toluene, and nitrogen was bubbled for more than 20 min. After stirring at room temperature for 30 min, the temperature was raised to 70 ℃-75 ℃ and reacted for 2 h-3 h, and then slowly cooled to 40 ℃-45 ℃. Intermediate 1 was dissolved in toluene and slowly injected into the reactor. The temperature was then raised to 110 ℃-115 ℃ and reacted in the dark for 12 h-15 h. The degree of reaction was detected by TLC thin-layer chromatography. After the reaction was complete, methanol was slowly added dropwise and stirred for 1 h-1.5 h to quench the reaction. After the reaction solution cooled to room temperature, the solvent was evaporated by rotary evaporator, and the solution was repeatedly extracted with dichloromethane three times. Intermediate 2 was obtained by column chromatography.

[0016] (2) Synthesis of C1: Intermediate 2, cuprous iodide, and palladium dichloride bis(triphenylphosphine) were placed in a reactor, and the reactor was evacuated and purged with nitrogen three times. Intermediate 3 was then injected into the reactor, followed by a mixed solution of triethylamine and tetrahydrofuran. The reactor was reacted at 70-75°C in the dark for 12-15 hours. The extent of the reaction was detected by TLC. After the reaction solution cooled to room temperature, the solvent was evaporated using a rotary evaporator, and the solution was repeatedly extracted with dichloromethane three times. C1 was obtained by column chromatography.

[0017] Further, in step (1), the molar ratio of decaborane, N,N-dimethylaniline and intermediate 1 is 1.2:3.6:1.

[0018] Further, in step (2), the molar ratio of intermediate 2, cuprous iodide, bis(triphenylphosphine)palladium dichloride, and intermediate 3 is 1:0.03:0.055:0.42.

[0019] Further, in step (2), the volume ratio of triethylamine to tetrahydrofuran in the mixed solution is 3:1, and the molar volume ratio of intermediate 3 to the mixed solution is 1:17.4.

[0020] The present invention also provides a chiral self-assembled material based on triazine-carborane, wherein the self-assembled material is prepared by self-assembly of a chiral reagent with the triazine-carborane material of claim 1.

[0021] Furthermore, the chiral reagent includes S / R-limonene, S / R-carvone, D / L-menthol, Valencia citrusene, tartaric acid, binaphthol and its derivatives.

[0022] Furthermore, the method for preparing the self-assembled material includes: self-assembling the triazine-carborane material C1 of claim 1 with different chiral reagents in ethanol and chloroform.

[0023] Furthermore, the molar ratio of the triazine-carborane material to different chiral reagents is 10:1; the volume ratio of ethanol to chloroform is 3:1; and the molar ratio of the triazine-carborane material to ethanol is 30:1.

[0024] Compared with existing technologies, the beneficial effects of this invention are: it uses triazine derivatives as hubs to connect spirofluorene and o-carborane respectively. This combines the three-dimensional spatial structure of the o-carborane molecule with the rigid structure of the triazine molecule, resulting in unique photoelectric properties. Simultaneously, the compound self-assembles with a chiral reagent to form a chiral structure, generating a CPL signal and increasing the GLUM value.

[0025] This invention combines triazine derivatives with spirofluorene-carborane and conducts extensive research on their photophysical properties, crystal structure, stacking mode, and thermal stability. Through π-π stacking interactions and the weak interaction between chiral reagents and C1, boron cluster microcrystal aggregates with different configurations are prepared, significantly improving the circular polarization value. This provides a robust structural model and theoretical basis for constructing the structure-property relationship between the structure of organic supramolecular self-assemblies and circularly polarized fluorescence, offering a novel strategy for designing new organic circularly polarized optoelectronic materials.

[0026] This invention will provide a basis for the design of boron cluster materials in optoelectronic applications and other fields. It also provides new ideas for the research of luminescent boron clusters in circularly polarized luminescence. Attached Figure Description

[0027] Figure 1 The 1H and 1C spectra of compound C1 are shown.

[0028] Figure 2 This is a crystal structure diagram of compound C1;

[0029] Figure 3 Thermodynamic properties of compound C1 are shown in the diagram.

[0030] Figure 4 This is a diagram showing the unimolecular structure and packing diagram of compound C1 after self-assembly with S-limonene;

[0031] Figure 5 The spectrum shows the self-assembly of compound C1 with limonene.

[0032] Figure 6 This is a scanning electron microscope image of the orthogonal experiment between compound C1 and limonene;

[0033] Figure 7 The spectrum of an orthogonal experiment between compound C1 and limonene;

[0034] Figure 8 The diagram shows the unimolecular structure and packing diagram of compound C1 assembled with carvone.

[0035] Figure 9 This is a diagram showing the unimolecular structure and packing diagram of compound C1 assembled with barumiene;

[0036] Figure 10 The spectrum of compound C1 assembled with carvone and Valencia orangeene;

[0037] Figure 11 Scanning electron microscope image of compound C1 assembled with carvone and Valencia citrusene;

[0038] Figure 12 Infrared comparison of compound C1 after assembly with S / R-carvone;

[0039] Figure 13 Scanning electron microscope image of compound C1 assembled with menthol;

[0040] Figure 14 The spectrum of compound C1 after assembly with menthol. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] The chemical reagents used in the experiment are listed in Table 1.

[0043] Table 1 Chemical reagents and chemicals used in the experiment

[0044]

[0045] Example 1

[0046] This invention discloses a triazine-carborane material, the compound of which is named C1, and has the following structural formula:

[0047] Formula C1.

[0048] The preparation method of triazine-carborane materials includes the following steps:

[0049] ; .

[0050] (1) Synthesis of intermediate 2: Decaborane (B10H14) (343.99 mg, 2.82 mmol) was weighed and placed in a double-necked flask. The flask was evacuated and purged with nitrogen three times. N,N-dimethylaniline (1.03 g, 8.45 mmol) was weighed and dissolved in 20 mL of toluene. Nitrogen was bubbled for more than 20 min. The mixture was stirred at room temperature for 30 min, then heated to 70 ℃ - 75 ℃ and reacted for 2 h - 2.5 h. The temperature was then slowly lowered to 40 ℃ - 45 ℃. Intermediate 1 (1.5 g, 2.35 mmol) was weighed and dissolved in toluene. The mixture was slowly injected into the double-necked flask, and then the temperature was raised to 110 ℃ - 115 ℃ and reacted in the dark for 12 h - 15 h. The reaction degree was detected by TLC thin-layer chromatography. After the reaction was complete, 50 mL - 60 mL of methanol was slowly added dropwise and stirred for 1 h - 1.5 h to quench the reaction. After the reaction solution cooled to room temperature, the solvent was evaporated using a rotary evaporator, and the solution was repeatedly extracted three times with dichloromethane. Column chromatography was then used to separate the product, yielding 1.5 g of a pale green solid, with a yield of 85.7%.

[0051] (2) Synthesis of C1: Intermediate 2 (2.0 g, 2.73 mmol), cuprous iodide (13.11 mg, 0.08 mmol), and palladium dichloride bis(triphenylphosphine) (80.6 mg, 0.15 mmol) were weighed and placed in a double-necked flask. The flask was evacuated three times to purge with nitrogen. Intermediate 3 (410.0 mg, 1.15 mmol) was then injected into the double-necked flask. 120 mL of a mixed solution of triethylamine and tetrahydrofuran (triethylamine:tetrahydrofuran volume ratio 3:1) was injected into the double-necked flask. The mixture was reacted at 75 °C in the dark for 12 h. The extent of the reaction was detected by TLC. After the reaction solution cooled to room temperature, the solvent was evaporated using a rotary evaporator. The mixture was extracted three times with dichloromethane. Column chromatography was used to separate the product, yielding 0.5 g of a yellow-green solid (C1), with a yield of 41.4%.

[0052] 1 H NMR (400 MHz, Chloroform-d) δ 8.90 (d, J = 1.5 Hz, 4H), 7.98 (s,2H), 7.82 (d, J = 8.6 Hz, 9H), 7.67 (s, 2H), 7.20 (dd, J = 8.2, 1.8 Hz, 1.58 (s, 12H).

[0053] The crystal structure data of compound C1 are shown in Table 2 below:

[0054] Table 2 Crystal structure data of compound C1

[0055]

[0056] The proton (a) and carbon (b) spectra of compound C1 are shown in the figure. Figure 1 As shown;

[0057] To further investigate the crystal structure of C1, single-crystal C1 particles were grown using a mixed solvent evaporation method. The good solvent was dichloromethane, and the poor solvent was methanol. The ambient temperature was room temperature. After filtering and drying, the obtained C1 single crystals were analyzed using a Bruker D8-advance X-ray diffractometer (λ = 1.54178) with graphite-monochromatic MoKα (λ = 0.71076) and CuKα radiation at 223 K. Crystallographic data were obtained, and the original crystallographic data were restored using the APEX3 program. The restored data were imported into Olex2 software for data analysis to obtain accurate crystallographic information files. Detailed single-crystal data are shown in Table 1. The crystal structure and molecular packing diagram were plotted using Mercury software as follows: Figure 2 As shown.

[0058] Thermodynamic tests were performed on C3 using thermogravimetric analysis (TGA) under a nitrogen atmosphere at a heating rate of 20 °C / min. The temperature at which the percentage of mass loss reached 2% was set as the thermal decomposition temperature (T0). d The temperature range was set from room temperature to 700 ℃. Differential scanning calorimetry (DSC) was used at a rate of 10 ℃ / min, with a temperature range of room temperature - 300 ℃ and back to room temperature.

[0059] like Figure 3 As shown in the TGA curve, C1 exhibits good thermodynamic properties. C1 only begins to decompose by 2% at 504 °C and by about 7% at 700 °C, indicating excellent thermal stability. Its ability to maintain its original physical and chemical properties at high temperatures is due to the generally high chemical and thermal stability of icosahedral carboranes. Therefore, the introduction of carborane improves the thermal stability of C1 to some extent, giving it great application potential in organic optoelectronic devices and other fields. DSC scan results show that the glass transition temperature of C1 is 233 °C, indicating that the material can maintain a rigid glassy state even at high temperatures. This is crucial for suppressing molecular motion in organic light-emitting diodes (OLEDs) and reducing non-radiative transition losses, thus contributing to improved device thermal stability and lifespan.

[0060] Example 2

[0061] C1 and limonene assembly:

[0062] C1 self-assembly process with S / R limonene: Weigh 7 mg C1, add 1 mL chloroform, and prepare a 7.0 mg / mL C1 (CHCl3) solution as a stock solution at room temperature. Take out 100 μL of the stock solution, add 120.0 μL of chiral limonene, 195.0 μL of CHCl3 and 585.0 μL of anhydrous ethanol, mix, and stir at room temperature for 20 min until dissolved and transparent, until aggregates appear.

[0063] To investigate the coupling mechanism and chiral regulation effect of the self-assembly of C1 and limonene, this invention uses C-1-Limonene, the self-assembled assembly of C1 and limonene, as the research object and conducts X-ray single-crystal diffraction (XC-XRD) analysis. First, the single-crystal sample underwent filtration and drying pretreatment. Then, absolute configuration determination was performed using a Bruker SMART APEX (II)-CCD single-crystal diffractometer equipped with a copper-palladium light source, successfully obtaining raw crystallographic data. After data reconstruction using APEX3 software, the results were imported into the Olex2 program system for structural analysis. Three-dimensional structure reconstruction was achieved through hydrogen atom introduction and differential Fourier transform techniques. Simultaneously, the least squares refinement strategy of the ShelXL program was used for iterative optimization of the data, ultimately obtaining the crystallographic information file. All crystal structure diagrams in this study were constructed based on the Mercury software platform, and the relevant crystallographic parameters have been systematically compiled in the C-1-Limonene crystal data report in Table 2. Figure 4 Multiple weak interactions (bond lengths ranging from 2.412 to 2.921 Å) were observed between chiral limonene and the C1 molecule of the luminescent material. These interactions act as key driving forces for chiral transfer, precisely inducing the luminescent material molecule to adopt a specific chiral conformation. The packing diagram along the b-axis shows the formation of helical chiral supramolecular chains in the crystal, with repeating unit sizes of 21.18 Å. This indicates that chirality was successfully transferred from the limonene molecule to the supramolecular structure of the luminescent material, providing a solid structural foundation for achieving circularly polarized luminescence.

[0064] To further investigate the luminescent properties and chiral characteristics of the assembly, a series of tests were conducted on the assembly, such as... Figure 5 As shown in (a), the circular dichroism spectrum illustrates that the chiral information of chiral limonene has been precisely transferred to the electronic transition process of the luminescent material through weak interactions in the crystal (such as CH…π, π…π stacking), inducing the luminescent material molecules to form a conformation that matches the chirality of limonene; the response range of 200–300 nm corresponds to the π-π* electronic transition of the luminescent material, proving that the chiral transfer occurs at the electronic structure level of the luminescent center, providing a molecular-level basis for subsequent circularly polarized luminescence.

[0065] Figure 5The consistency of the emission peak positions in (b) PL spectra indicates that the introduction of chiral limonene only transmits chiral information and does not change the intrinsic luminescence properties of the luminescent material; the broad half-width at half-maximum (HWHM) is due to the diversity of excited-state relaxation caused by weak interactions in supramolecular assembly; the intensity difference may be related to the stronger weak interaction between R-type limonene and the luminescent material and the more significant suppression of nonradiative transitions.

[0066] like Figure 5 As shown in (c) of the CPL spectrum: the mirror-symmetric CPL signal directly proves that circularly polarized light was generated during the luminescence process, and the chiral direction is completely matched with the chirality of limonene, verifying the complete transmission path of "chiral limonene → weak interaction → chiral conformation of luminescent material → circularly polarized luminescence"; the correspondence between the emission peak and the PL spectrum indicates that the CPL signal originates from the excited state of the luminescent material. Combined with the helical stacking characteristics of the crystal structure, it further confirms that chiral supramolecular assembly is the structural basis of circularly polarized luminescence.

[0067] Figure 5 The g-value plot (d) in the figure shows that the g values ​​of the two enantiomers are: lum The values ​​exhibit strict mirror symmetry, ranging from approximately ±0.004 to ±0.008, which is considered a relatively high asymmetry factor level among organic light-emitting materials. lum The value directly reflects the chiral transfer efficiency. Values ​​ranging from ±0.004 to ±0.008 indicate that the system has a high chiral transfer efficiency, which is highly correlated with the stable weak interactions and helical stacking in the crystal structure. The mirror-symmetric signal further verifies the enantioselectivity of chiral transfer, providing key parameters for the design of high-performance circularly polarized luminescent materials.

[0068] Example 3

[0069] Based on Example 2, the inventors further investigated the regulatory effect of chiral enantiomer excess (χ) on the properties of the assembly:

[0070] The formula for calculating the χ value is as follows:

[0071] ;

[0072] Solution A: Take 7.7 mg C1, add 1.1 mL of chloroform, and prepare a 7.0 mg / mL C1 (CHCl3) solution as a stock solution at room temperature;

[0073] Solution B: S-limonene and R-limonene were mixed to obtain limonene solutions with different excess values ​​χ;

[0074] Where S and R represent the volumes of S-limonene and R-limonene, respectively.

[0075] C-1 self-assembly with chiral limonene: Take 100 μL of solution A and 120 μL of solution B, mix them evenly, add 585 μL of ethanol and 195 μL of chloroform, and let stand at 30 ℃ until aggregates appear.

[0076] In solution B, S-limonene and R-limonene were mixed to obtain limonene solutions with different enantiomeric excess values ​​χ: gradients of ±100, ±80, ±60, ±40, ±20, and 0% were selected for comparison.

[0077] The solution obtained by mixing 120 μL of S-limonene and 0 μL of R-limonene is χ = +100%; the solution obtained by mixing 120 μL of R-limonene and 0 μL of S-limonene is χ = -100%.

[0078] ±80: A solution with χ = +80% can be obtained by mixing 108 μL of S-limonene and 12 μL of R-limonene; a solution with χ = -80% can be obtained by mixing 108 μL of R-limonene and 12 μL of S-limonene.

[0079] ±60: A solution with χ = +60% can be obtained by mixing 96 μL of S-limonene and 24 μL of R-limonene; a solution with χ = -60% can be obtained by mixing 96 μL of R-limonene and 24 μL of S-limonene.

[0080] ±40: A solution with χ = +40% can be obtained by mixing 84 μL of S-limonene and 36 μL of R-limonene; a solution with χ = -40% can be obtained by mixing 84 μL of R-limonene and 36 μL of S-limonene.

[0081] ±20: A solution with χ = +20% can be obtained by mixing 72 μL of S-limonene and 48 μL of R-limonene; a solution with χ = -20% can be obtained by mixing 72 μL of R-limonene and 48 μL of S-limonene.

[0082] ±0: A solution with χ = +0% can be obtained by mixing 60 μL of S-limonene and 60 μL of R-limonene; a solution with χ = -0% can be obtained by mixing 60 μL of R-limonene and 60 μL of S-limonene.

[0083] To investigate how chirality drives the evolution of nanoscale building blocks towards multi-level structures, the experimental system systematically studied the degree of chiral enantiomer excess (χ) and its effect on assembly morphology. By adjusting the χ value of limonene (from a completely racemic state χ=0 to a single chiral excess state χ=±100) combined with scanning electron microscopy (SEM), the results were obtained. Figure 6Dynamic tracking of morphological evolution. Microscopic observation of crystal shape corroborates assembly behavior. The results show that, under constant reactant concentration, changing only χ can yield a continuous morphological transformation from simple crystals to complex hierarchical structures, providing key experimental evidence for revealing the chiral regulation mechanism.

[0084] The spectrum of the orthogonal experiment between compound C1 and limonene is shown below. Figure 7 As shown: (a): PL spectrum of the orthogonal experiment of compound C1 with limonene; (b): CPL spectrum of the orthogonal experiment of compound C1 with limonene; (c): luminescence asymmetry factor diagram of the orthogonal experiment of compound C1 with limonene. From the spectrum of the orthogonal experiment ( Figure 7 It can be seen that as χ increases, the CPL strength and g of the assembled structure increase. lum The results showed that, under constant reactant concentration, changing only χ could alter the intensity and luminescence asymmetry factor of CPL.

[0085] Example 4

[0086] C1 and carvone assembly:

[0087] C1 self-assembly process with carvone: Weigh 7 mg of C1, add 1 mL of chloroform, and prepare a 7.0 mg / mL C1(CHCl3) solution as a stock solution at room temperature. Take out 100 μL of the stock solution, add 120.0 μL of chiral carvone, 195.0 μL of CHCl3 and 585.0 μL of anhydrous ethanol, mix, and stir at room temperature for 20 min until dissolved and transparent, until aggregates appear.

[0088] By using single-crystal X-ray diffraction analysis and Mercury software to refine and visualize the supramolecular structure, the molecular arrangement, non-covalent interaction mode, and long-range stacking characteristics of chiral carvone and luminescent material C1 were clarified, revealing the structural essence of chiral transfer at the atomic level.

[0089] The unimolecular structure and packing diagram of compound C1 assembled with carvone are shown below. Figure 8 As shown, the crystal structure diagram is obtained by using an X-ray diffractometer to detect the arrangement of crystals and determine the chiral structure.

[0090] like Figure 8 As shown: From the perspective of single-molecule configuration, the target luminescent material molecule exhibits the characteristics of a rigid conjugated skeleton. Due to the fixed spatial orientation of the conjugated π system, the molecular skeleton does not have a chiral center and is a typical achiral luminescent parent. Chiral carvone, as an exogenous chiral inducing unit, provides a molecular basis for chiral transfer by directional constraint on the spatial conformation of the luminescent material molecule through steric hindrance and electronic effects.

[0091] Weak intermolecular interactions are the core driving force for chiral transfer. The Mercury structure clearly shows multiple redirected non-covalent interactions between the chiral carvone and the conjugated framework of the luminescent material. The labeled bond lengths are 2.730 Å, 2.475 Å, and 2.464 Å, all within the effective range of classical weak intermolecular interactions (2.4-2.8 Å), and can be attributed to C–H…π interactions, C–H…O hydrogen bonds, and polar -π weak electrostatic interactions. These short-range interactions are highly directional and selective, and are not random intermolecular forces. Instead, they "anchor" the chiral information of the chiral carvone to the non-chiral luminescent material molecule in the form of non-covalent bonds, forcibly inducing the conjugated framework of the luminescent material to form a spatial conformation with a specific chiral orientation, effectively avoiding conformational disorder and racemization, and forming a molecular bridge for chiral transfer.

[0092] At the long-range supramolecular stacking level, the stacking diagram along the b-axis of the crystal shows that chiral carvone and the luminescent material assemble alternately through the aforementioned directional weak interactions, forming a supramolecular chain structure with one-dimensional helical chirality. The repeating stacking period of the chain segments is precisely 20.42 Å, exhibiting a highly ordered long-range chiral arrangement. The chiral direction of this helical stacking is entirely determined by the absolute configuration of the chiral carvone. The luminescent material molecules, as backbone units, extend orderly along the chiral helical axis, realizing the cross-scale transfer of chiral information from the molecular-level chiral source to the supramolecular-level assembly.

[0093] Overall, chiral carvone achieves chiral induction of the molecular conformation of achiral luminescent materials through directional weak interactions at 2.730 Å, 2.475 Å, and 2.464 Å, and further drives the formation of one-dimensional chiral helical supramolecular stacks with a period of 20.42 Å. This provides direct and conclusive crystallographic evidence for the subsequent generation of chiral optical responses such as circularly polarized emission (CPL) and circular dichroism (CD) in the materials, and also confirms that the strategy of supramolecular chirality transfer based on terpene chiral small molecules through non-covalent interactions is highly feasible.

[0094] Assembly of C1 and balombylenene: The method is the same as that for the assembly of C1 and carvone, only the chiral reagent carvone is changed to balombylenene. The unimolecular structure and packing diagram of the assembled compound C1 and balombylenene are shown below. Figure 9 As shown, we have successfully achieved chiral induction and long-range transfer of chirality in compound C1 by chiral balombylenene, and its crystal structure clearly reveals a multi-level chiral transfer mechanism.

[0095] Within a single assembly unit, the synthesized compound and balombylen form a stable supramolecular recognition site through a key non-covalent interaction (bond length 1.898 Å). The chiral center of balombylen breaks the original symmetry of the synthesized compound through steric hindrance and weak interactions (such as CH…π and van der Waals forces), inducing it to adopt a specific chiral conformation, thus laying the molecular foundation for subsequent chiral transfer.

[0096] The two assembly units form a dimer via balombylen bridging, with critical interaction distances of 2.927 Å and 2.577 Å between balombylen bridging and the two units, respectively, falling within the typical range of non-covalent interactions. Under the chiral induction of balombylen bridging, the two units exhibit a mirror-symmetric conformation, effectively amplifying the chirality from molecular chirality to dimer chirality and significantly enhancing the system's chiral signal.

[0097] The assemblies extend along crystallographic directions, forming a one-dimensional helical chain with a uniform helical orientation. The spacing between repeating units within the dashed box is 20.90 Å, which is the pitch of the helix, indicating that chiral information is transmitted in an ordered manner over long distances. Different molecular chains (red, blue, and green) all adopt the same helical orientation under the induction of barambialene, ultimately forming a supramolecular crystal with macroscopic chirality.

[0098] This chiral transfer process, from molecular recognition to dimer amplification and then to long-range helical assembly, provides important structural basis for the design of novel chiral supramolecular materials. This system has potential applications in asymmetric catalysis, chiral separation, and chiral optical materials.

[0099] Figure 10 (a) Circular dichroism (PD) spectrum of compound C1 assembled with carvone and Valencia mansene; (b) Photonic spectral density (PL) spectrum of compound C1 assembled with carvone and Valencia mansene; (c) Photonic spectral density (CPL) spectrum of compound C1 assembled with carvone and Valencia mansene; (d) Photoluminescence asymmetry factor of compound C1 assembled with carvone and Valencia mansene. These figures demonstrate the successful assembly of C1 with the chiral reagent carvone and Valencia mansene.

[0100] Figure 11 (a–d) shows the scanning electron microscope characterization results of the co-crystal products constructed by chiral carvone and the target luminescent material. The results visually demonstrate the macroscopic morphology, size distribution, surface features and aggregation state of the co-crystal materials under different growth conditions, and confirm the directional regulation effect of chiral carvone on the crystal growth and supramolecular assembly of the luminescent material from the microscopic morphology level.

[0101] To verify the intermolecular interaction between chiral carvone and the target luminescent material C1, and to reveal the formation mechanism of supramolecular cocrystals, Fourier transform infrared spectroscopy was performed on S / R-carvone, pure C1, and the chiral cocrystal products C-1-(S)-Carvone and C-1-(R)-Carvone. Figure 12 As shown, the test range is 4000~400 cm. -1 The spectral results clearly demonstrate the vibrational shifts and peak shape evolution of each characteristic functional group, providing direct spectroscopic evidence for supramolecular interactions in chiral transfer.

[0102] Characteristic absorption peaks were assigned and analyzed one by one: In the spectrum of pure chiral carvone, 1700 cm⁻¹ -1 The C=O carbonyl stretching vibration peak nearby is a characteristic functional group peak of carvone, belonging to the characteristic stretching vibration of the carbonyl group of terpene ketones; in the pure C1 spectrum, 2500~3000 cm⁻¹ -1 The BH bond stretching vibration peak in the range of 1600–1650 cm⁻¹ is a characteristic marker peak for C1 in luminescent materials. -1 The absorption peaks at these locations are attributed to the stretching vibrations of the C=C double bonds in the molecular skeleton, and these characteristic peaks can serve as core markers for molecular recognition.

[0103] Comparing the spectra of the pure raw material and the cocrystallized product, it can be seen that no new covalent bond characteristic absorption peaks appeared in the infrared spectra of the cocrystallized products C-1-(S)-Carvone and C-1-(R)-Carvone, proving that no chemical reaction occurred between chiral carvone and C-1 to form a covalently bonded product, and the two are combined by non-covalent supramolecular interaction. Meanwhile, the C=O carbonyl peak of carvone in the eutectic system showed a significant red shift and broadening, while the BH characteristic vibrational peak and C=C double bond peak of C-1 showed significant shifts and weakening in intensity. The evolution of the peak shape and position is a typical characteristic of weak interactions such as hydrogen bonding, CH…π interaction, and dipole-dipole electrostatic interaction between molecules. The carbonyl group of carvone acts as a hydrogen bond acceptor, forming directional intermolecular forces with BH or unsaturated CH in the C1 molecule, which causes a change in the functional group bond constant, and thus manifests as a shift and broadening of the vibrational peak. This change is completely consistent with the short-range weak interactions (1.898 Å, 2.277 Å) observed in single-crystal diffraction, directly confirming that chiral carvone and C-1 construct a stable supramolecular eutectic structure through directional weak interactions.

[0104] In summary, the infrared spectroscopy results confirm that S / R-carvone and the luminescent material C-1 form a supramolecular eutectic through a weak non-covalent interaction, without the formation of covalent bonds. The spectral consistency of the enantiomer system proves that the two chiral configurations have the same interaction mode, while the shift and broadening of the characteristic peaks directly reflect the existence of strong supramolecular forces between molecules. This provides key spectroscopic support for the efficient chiral transfer of chiral carvone to C-1, and also forms a complete structure-spectral correlation evidence chain with the chiral helical stacking in the crystal structure and the regular eutectic morphology of SEM.

[0105] C1 and menthol assembly: The method is the same as that for C1 and carvone assembly, except that the chiral reagent carvone is replaced with menthol.

[0106] Figure 13 , 14 The images show the SEM images and spectra of the menthol and C1 assembly, respectively. Figure 14 (a): Circular dichroism spectrum of compound C1 assembled with menthol; (b): PL spectrum of compound C1 assembled with menthol; (c): CPL spectrum of compound C1 assembled with menthol; (d): luminescence asymmetry factor of compound C1 assembled with menthol. This also confirms that supramolecular forces successfully transferred the chirality of the chiral reagent to compound C1.

[0107] The crystal data of C1, limonene, and carvone after assembly are shown in Tables 3 and 4:

[0108] Table 3. Crystal structure of compound C1 self-assembled with limonene

[0109]

[0110] Table 4. Crystal structure of compound C1 self-assembled with carvone

[0111]

[0112] Self-assembly-driven formation of ordered supramolecular structures

[0113] This invention successfully constructed a supramolecular aggregate with a two-dimensional structure by co-assembling a triazine-carborane acceptor with a chiral reagent. PXRD results showed that the molecules were arranged in an orderly manner mainly through π-π stacking of the triazine ring, hydrophobic interactions of the carborane, and synergistic effects of hydrogen bonds, forming a stable crystalline structure.

[0114] Efficient chirality transfer and amplification

[0115] The CD spectroscopy test of this invention shows that the assembly exhibits a significant chiral signal in the ultraviolet-visible region, while the monomer compound does not have this signal, proving that chiral information has been efficiently transferred from the chiral reagent to the achiral / chiral triazine carborane skeleton, and chiral amplification has been achieved at the supramolecular level.

[0116] Excellent circularly polarized fluorescence performance

[0117] Benefiting from the ordered chiral stacking mode, the supramolecular assembly exhibits strong circularly polarized fluorescence (CPL) emission. Compared with the monomer, the fluorescence quantum yield of the assembly is significantly improved, and it has a larger asymmetry factor, indicating that the rigid framework of triazine-carborane effectively suppresses nonradiative transitions, while the chiral microenvironment endows the material with excellent chiral optical properties.

[0118] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0119] It should be noted that the above content merely illustrates the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. For those skilled in the art, various improvements and modifications can be made without departing from the principle of the present invention, and all such improvements and modifications fall within the scope of protection of the claims of the present invention.

Claims

1. A triazine-carborane material, characterized in that, The structure of the triazine-carborane material is shown in Formula C1: Formula C1.

2. The method for preparing a triazine-carborane material according to claim 1, characterized in that, The process flow of the preparation method is as follows: ； 。 3. The method for preparing a triazine-carborane material according to claim 2, characterized in that, The preparation method specifically includes the following steps: (1) Synthesis of intermediate 2: Decaborane was placed in a reactor and evacuated to replace nitrogen three times. N,N-dimethylaniline was dissolved in toluene. Nitrogen was bubbled for more than 20 min. After stirring at room temperature for 30 min, the temperature was raised to 70 ℃ - 75 ℃ and reacted for 2 h - 3 h. Then the temperature was slowly lowered to 40 ℃ - 45 ℃. Intermediate 1 was dissolved in toluene and slowly injected into the reactor. Then the temperature was raised to 110 ℃ - 115 ℃ and reacted in the dark for 12 h - 15 h. Intermediate 2 was obtained. (2) Synthesis of C1: Intermediate 2, cuprous iodide, and palladium dichloride of bis(triphenylphosphine) were placed in a reactor, and the nitrogen gas was replaced by vacuum three times. Intermediate 3 was injected into the reactor, and a mixed solution of triethylamine and tetrahydrofuran was injected into the reactor. The reactor was reacted at 70 ℃ - 75 ℃ in the dark for 12 h - 15 h to obtain C1.

4. The method for preparing a triazine-carborane material according to claim 3, characterized in that, In step (1), the molar ratio of decaborane, N,N-dimethylaniline and intermediate 1 is 1.2:3.6:

1.

5. The method for preparing a triazine-carborane material according to claim 3, characterized in that, In step (2), the molar ratio of intermediate 2, cuprous iodide, bis(triphenylphosphine)palladium dichloride and intermediate 3 is 1:0.03:0.055:0.

42.

6. The method for preparing a triazine-carborane material according to claim 3, characterized in that, In step (2), the volume ratio of triethylamine to tetrahydrofuran in the mixed solution is 3:1, and the molar volume ratio of intermediate 3 to the mixed solution is 1:17.

4.

7. A chiral self-assembled material based on triazine-carborane, characterized in that, The self-assembled material is prepared by self-assembly of a chiral reagent with the triazine-carborane material of claim 1.

8. A chiral self-assembly material based on triazine-carborane according to claim 7, characterized in that, The chiral reagents include S / R-limonene, S / R-carvone, D / L-menthol, Valencia citrusene, tartaric acid, binaphthol and their derivatives.

9. A chiral self-assembly material based on triazine-carborane according to claim 7, characterized in that, The method for preparing the self-assembled material includes: self-assembling the triazine-carborane material C1 as described in claim 1 with different chiral reagents in ethanol and chloroform.

10. A chiral self-assembled material based on triazine-carborane according to claim 9, characterized in that, The molar ratio of the triazine-carborane material to different chiral reagents is 10:1; the volume ratio of ethanol to chloroform is 3:1; and the molar ratio of the triazine-carborane material to ethanol is 30:1.

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