Solvent-Induced Symmetry-Breaking Charge Transfer in an Octupolar Triphenylamine Derivative Resolved with Transient Fluorescence Spectroscopy  

瞬态荧光方法研究溶剂诱导的三苯胺衍生物的对称性破缺电荷转移动力学（英文）

作　　者：Zhuoran Kuang Hongwei Song Yuanyuan Guo Qianjin Guo Andong Xia 匡卓然;宋宏伟;郭媛媛;郭前进;夏安东(中国科学院化学研究所,光化学重点实验室,北京分子科学国家研究中心,北京100190;中国科学院大学,北京100049)

机构地区：[1]Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China [2]University of Chinese Academy of Sciences, Beijing 100049, China

出　　处：《Chinese Journal of Chemical Physics》2019年第1期59-66,I0001,共9页化学物理学报（英文）

基　　金：supported by the National Natural Science Foundation of China (No.21673252, No.21333012, No.21672211, and No.21773252, No.21827803);the Strategic Priority Research Program of the Chinese Academy of Sciences (No.XDB12020200)

摘　　要：The excited-state symmetry-breaking charge transfer (SBCT) dynamics in quadrupolar or octupolar molecules without clear infrared markers is usually hard to be tracked directly. In this work, on the basis of the evolution of instantaneous emission dipole moment obtained by femtosecond transient fluorescence spectroscopy, we presented a real-time characterization of the solvent-induced SBCT dynamics in an octupolar triphenylamine derivative. While the emission dipole moment of the octupolar trimer in weakly polar toluene changes little during the excited-state relaxation, it exhibits a fast reduction in a few picoseconds in strongly polar tetrahydrofuran. In comparison with the uorescence dynamics of dipolar monomer, we deduced that the emitting state of the octupolar trimer in strongly polar solvent, which undergoes solvent-induced structural uctuation, changes from exciton-coupled octupolar to excitation localized dipolar symmetry. In weakly polar solvent, the octupolar symmetry of the trimer is largely preserved during the solvation stabilization.

关 键 词：Symmetry breaking charge transfer Solvent effect Transient fluorescence spectroscopy Emission dipole moment 

分 类 号：O643.12[理学—物理化学] O621.25[理学—化学]