多功能有机硼配合物的不对称修饰、构效关系和应用性能研究

The dual state emitting luminogens, force-induced multicolor or enhanced fluorescence switching have exhibited practical values in many fields such as anti-counterfeiting, memory chips, pressure sensor and so on. However, the current understanding of the intrinsic mechanism of these functional materials is mainly derived from the analysis and interpretation of the corresponding properties. Thus, it's too soon to give a definite design rules. The project is intend to combine aggregation induced emission effect, halogen atom effect, hydrophilic and hydrophobic interactions, intramolecular charge transfer with planar molecular configuration of organic boron complex, tune the molecular packing, degree of conjugation, orbital energy level distribution and intermolecular force by asymmetric modification of organic boron complex and crystallization induction effect of small molecules, and obtain excellent dual state emitting luminogens, force-induced multicolor or enhanced fluorescence switchings. Based on theoretical calculation and a series of tests, such as single-crystal X-ray diffraction, UV-Vis absorption spectrum, fluorescence emission spectrum, fluorescence lifetime, scanning electron microscope and X-ray diffraction, etc., molecular conformation, stacking morphology, intermolecular force, molecular orbital energy level distribution and their effect on the photophysical properties are investigated and discussed. Furthermore, the structure-photophysical properties of boron complex will be established, and theoretical guidance for the molecular design and performance optimization will be provided. Finally, by the study of anti-counterfeiting encoding, pressure detection and mechanochromic reversibility, the corresponding application performance of organic boron complex are evaluated.

二元性荧光色团，力致多重和荧光增强性色变开关在防伪、记忆芯片和压力传感等诸多领域具有实用价值。然而，当前对其内在机理的认识主要源于材料性能分析和解释，尚不能形成有效的设计规则。本项目拟结合聚集诱导效应、卤原子效应、亲/疏水相互作用、分子内电荷传递和有机硼配合物的平面化分子构型，通过不对称有机硼配合物的分子设计和小分子结晶诱导效应，调节分子堆积、分子共轭程度，分子间作用力和分子轨道能级分布，得到性能优良的二元性荧光色团，力致多重和荧光增强性色变开关，借助理论计算、X-单晶衍射、紫外可见吸收光谱、荧光发射光谱、荧光寿命、扫描电镜、X射线衍射等手段，研究分子构象、堆积形态、分子间作用力和分子轨道能级分布对材料光物理性能的影响，建立材料结构与光物理性能之间的构效关系，并为材料的分子设计和性能优化提供理论指导。通过防伪编码、压力检测和力致色变可逆性研究，评价有机硼配合物的防伪和压力检测性能。

多态发射、多晶态和多重力致色变材料在防伪、存储芯片、压力传感器等方面显示出实用价值。然而，这些功能材料的内在机制研究仍处于起步阶段。本项目通过四苯乙烯与芳香胺、苯醚或芳杂环结合，设计并合成了一系列不对称有机硼配合物。其中TPEDKBF2DMeA、TPEDKBF2Ca和TPEDKBF2DBeA分别表现出聚集猝灭、AIE和双态发射（DSE）荧光特征。此外，TPEDKBF2Ca、TPEDKBF2DBeA和TPEDKBF2DMeA依次显示可逆多色开关、蓝移荧光发射和显著的发光增强，以及在外部机械力作用下可忽略的波长移动。晶体分析和理论计算表明，分子堆积模式是影响光学和机械变色性能的关键因素。同时，这项工作表明芳胺取代基可以调节有机荧光团的多态发射特性，这为多态发射体和机械变色材料的分子设计提供了深入理解。分子异构体TPEB2F、TPEB3F、TPEB2T和TPEB3T具有微小的结构差异，表现出高对比度多晶态，这是获得多色转化材料的高效途径。理论计算表明，形成多晶型的关键主要取决于堆积分子对和培养溶剂的偶极矩，而不是堆积分子对的最小能量和单个分子的偶极矩。晶体分析表明，机械变色不仅与分子间的堆积和排列有关，还与晶体体系、空间群和密度有关。TPEDKBF2OMe、TPEDKBF2OEt、TPEDKBF2OBu、TPEDKBF2OHe和PEDKBF2ONo显示出显著的AIE特性和多色开关。然而，随着烷基链长度的增加，配合物表现出不规则的机械变色行为。晶体分析表明，这些配合物具有相似的J型堆积，但不同的孔结构或头对头堆积，导致TPEDKBF2OMe、TPEDKBF2OBu和TPEDKBF2OHe在压碎前后发生明显的波长偏移。对于TPEDKBF2ONe，柔性长烷基链的堆积容易被破坏，并保持头-头J型堆积不会发生很大变化，从而防止荧光发射波长产生明显蓝移。第一次，机械变色的内在机制可归因于超声波处理和粉碎下J型堆叠的坍塌，疏水作用和长烷基链的非极性环境可以有效地增强非极性小分子的固态荧光发射和嵌入。最后，硼配合物的结构-光物理性质将为分子设计和性能优化提供理论指导。