Lin Xuerong, Ouyang Guanghui, Liu Minghua
Henan Institute of Advanced Technology, Zhengzhou University, Zhengzhou 450052, China.
CAS Key Laboratory of Colloid, Interface and Thermodynamics, Institute of Chemistry, Chinese Academy of Sciences, No. 2 North First Street, Zhongguancun, Beijing 100190, China.
ACS Appl Mater Interfaces. 2023 Apr 19;15(15):19741-19749. doi: 10.1021/acsami.3c02237. Epub 2023 Apr 10.
Despite significant achievements in the field of chiroptical organic materials, the full utilization of both the excited state and ground state chiroptical properties in a single supramolecular system is still rarely disclosed. Here, we report that the rational combination of the charge-transfer (CT) interaction with the spacer effect and controlled protonation of π-histidine leads to chiroptical organic π-materials with both circularly polarized luminescence (CPL) and the supramolecular chirality-directed chiroptical photothermic effect. Three pyrene-conjugated histidine derivatives with varied acyl linkers (PyHis, PyC1His, and PyC3His) were designed to coassemble with electron-deficient 1,2,4,5-tetracyanobenzene (TCNB), leading to the formation of supramolecular CT complexes with intense orange to red CPL depending on the linker length. The linker length also affected the protonation-induced CPL responsiveness of the corresponding CT assemblies. Upon protonation of the histidine moiety, PyC3His/TCNB CT assemblies exhibited an inverted CPL signal, while PyHis/TCNB pairs gave quenched CPL due to the disassembly. The protonation-controlled PyC3His/TCNB CT assemblies at varied pH values showed different chiroptical photothermic effects (CPEs) for the same incident chiral light despite the molecular chirality of PyC3His remaining unchanged, supporting an interesting supramolecular chirality-directed photothermic effect.
尽管在手性光有机材料领域取得了显著成就，但在单个超分子体系中充分利用激发态和基态手性光性质的情况仍然鲜有报道。在此，我们报道电荷转移（CT）相互作用与间隔效应以及π-组氨酸的可控质子化的合理组合，可产生兼具圆偏振发光（CPL）和超分子手性导向的手性光热效应的手性光有机π材料。设计了三种带有不同酰基连接基的芘共轭组氨酸衍生物（PyHis、PyC1His和PyC3His）与缺电子的1,2,4,5-四氰基苯（TCNB）共组装，根据连接基长度形成具有强烈橙色到红色CPL的超分子CT配合物。连接基长度也影响相应CT组装体的质子化诱导CPL响应性。组氨酸部分质子化后，PyC3His/TCNB CT组装体表现出反向CPL信号，而PyHis/TCNB对由于解离导致CPL淬灭。尽管PyC3His的分子手性保持不变，但在不同pH值下质子化控制的PyC3His/TCNB CT组装体对相同入射手性光表现出不同的手性光热效应（CPE），这支持了一种有趣的超分子手性导向光热效应。
