Triphenylamines consisting of bulky 3,5-di–tert–butyl–4-anisyl group:Synthesis, redox properties and their radical cation species

作     者：Manfei Zhou Lijun Mao Yan-Fei Niu Xiao-Li Zhao Xueliang Shi Hai-Bo Yang Manfei Zhou;Lijun Mao;Yan-Fei Niu;Xiao-Li Zhao;Xueliang Shi;Hai-Bo Yang

作者机构：Shanghai Key Laboratory of Green Chemistry and Chemical ProcessesSchool of Chemistry and Molecular EngineeringEast China Normal UniversityShanghai 200062China 

出 版 物：《Chinese Chemical Letters》 (中国化学快报（英文版）)

年 卷 期：2022年第33卷第4期

页      面：1870-1874页

核心收录：

学科分类：081702[工学-化学工艺] 08[工学] 0817[工学-化学工程与技术] 0703[理学-化学] 

基　　金：financially supported by the National Natural Science Foundation of China (Nos. 22071061 and 52003081) Shanghai Sailing Pro-gram (No. 19YF1412900) Microscale Magnetic Resonance Platform of ECNU。 

主　　题：Triphenylamine Radical cation Stability Redox Steric protection 

摘      要：Triphenylamine(TPA) derivatives have been widely used as useful building blocks for diverse functional materials because of their excellent redox activity. Most of the molecular structures of TPA-based organic functional materials contain 4-anisyl groups, which on one hand could reduce their oxidation potential and on the other hand significantly delocalize the spin density of the resultant TPA radical cation species and enhance their stability. However, molecular-level investigation of the redox behavior of triphenylamines consisting of 4-anisyl group and the electronic structures of their radical cation species has not been reported in the literature. Herein, we design a series of triphenylamines consisting of one, two, or three 3,5-di–tert–butyl–4-anisyl groups and investigate their redox behaviors and corresponding radical cation species. We disclose that the resonance hybrid and steric protection could both contribute to the stability of triphenylamine radical cations. Moreover, further oxidation leads to an unexpected oxidative demethylation. The findings in this work may reveal new insights for the understanding of the unique redox properties of 4-anisyl substituted triphenylamines.