Impact of Methoxy Substituents on Thermally Activated Delayed Fluorescence and Room-Temperature Phosphorescence in All-Organic Donor–Acceptor Systems
作者:Jonathan S. Ward、Roberto S. Nobuyasu、Mark A. Fox、Juan A. Aguilar、David Hall、Andrei S. Batsanov、Zhongjie Ren、Fernando B. Dias、Martin R. Bryce
DOI:10.1021/acs.joc.8b02848
日期:2019.4.5
used to characterize asymmetric methoxy-substituted derivative 3b, which is chiral at N because of an extremely high flipping barrier at the phenothiazine N atom. Based on hybrid-density functional theory computations, the methoxy substituents tune the relative stabilities of the axial conformers with respect to equatorial conformers of the phenothiazine units, depending on their substitution position
已知在有机D–A–D和D–A系统中会发生热激活延迟荧光(TADF)和室温磷光(RTP),其中供体基团包含吩噻嗪单元,受体为二苯并噻吩-S,S-二氧化物。这项研究报告了一种新的D–A和四个新的D–A–D系统的合成和表征,这些系统在吩噻嗪上具有甲氧基,以检查它们对zeonex基质中发射性质的影响。X射线分析和高度专业化的NMR技术用于表征不对称甲氧基取代的衍生物3b,由于在吩噻嗪N原子上具有很高的翻转势垒,因此在N上是手性的。基于杂化密度泛函理论计算,甲氧基取代基根据其取代位置来调节轴向构象异构体相对于吩噻嗪单元的赤道构象异构体的相对稳定性。与母系D–A–D系统相比,这种构象效应显着影响TADF和RTP贡献。还表明,zeonex中D–A–D和D–A系统的赤道形式表现出TADF。另外,在仅有轴向构象体的D–A–D系统中,甲氧基可促进发光。这项工作揭示了更有效的TADF和RTP分子的进一步设计机会。