文献类型：期刊文献

英文题名：Phenothiazine Scope: Steric Strain Induced Planarization and Excimer Formation

作者：Chen, Deng-Gao[1];Chen, Yi[1,2,3];Wu, Cheng-Ham[1];Chen, Yi-An[1];Chen, Meng-Chi[1];Lin, Jia-An[1];Huang, Chun-Ying[1];Su, Jianhua[2,3];Tian, He[2,3];Chou, Pi-Tai[1]

机构：[1]Natl Taiwan Univ, Dept Chem, Taipei 10617, Taiwan;[2]East China Univ Sci & Technol, Key Lab Adv Mat, Shanghai 200237, Peoples R China;[3]East China Univ Sci & Technol, Inst Fine Chem, Shanghai 200237, Peoples R China

年份：2019

卷号：58

期号：38

起止页码：13297

外文期刊名：ANGEWANDTE CHEMIE-INTERNATIONAL EDITION

收录：;EI(收录号：20193407330120);WOS:【SCI-EXPANDED(收录号:WOS:000480702100001)】；

基金：P.-T.C. thanks the Ministry of Science and Technology (MOST), featured areas research program within the framework of the Higher Education Sprout Project administrated by Ministry of Education (MOE) of Taiwan, for financial support. H.T. thanks NSFC/China (21788102) for financial support. We are grateful to the National Center for the valuable computer time and facilities at the High-performance Computing (NCHC) of Taiwan for.

语种：英文

外文关键词：charge transfer; conformation analysis; excimers; heterocycles; steric hindrance

摘要：Phenothiazine derivatives based on the 10-phenyl-10H-phenothiazine (NAS) chromophore, namely 7-phenyl-7H-benzo[c]phenothiazine (NAS-1) and 12-phenyl-12H-benzo[a]phenothiazine (NAS-2), were designed and synthesized. NAS-1 and NAS-2 are constitutional isomers with different steric strains imposed on the phenothiazine core moiety. In solution, the more-strained NAS-2 possesses a bent structure and undergoes photoinduced structural planarization (PISP). In the crystal, despite the absence of PISP, bent NAS-2 exhibits prominent excimer emission as well as emission mechanochromism, which is not observed in the planar-like NAS and NAS-1. This unconventional observation results from the bent core structure facilitating pi-pi stacking of the peripheral naphthalene moieties. Two-photon-coupled depth-dependent emission shows spectral differences between the surface and kernel of the NAS-2 crystal, and is believed to be a general phenomenon, at least in part, for materials exhibiting emission mechanochromism.