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Molecular Engineering through Control of Structural Deformation for Highly Efficient Ultralong Organic Phosphorescence
Author(s) -
Yin Zheng,
Gu Mingxing,
Ma Huili,
Jiang Xueyan,
Zhi Jiahuan,
Wang Yafei,
Yang Huifang,
Zhu Weiguo,
An Zhongfu
Publication year - 2021
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202011830
Subject(s) - phosphorescence , intersystem crossing , phosphor , carbazole , photochemistry , chemistry , intermolecular force , methylene , intramolecular force , materials science , molecule , organic chemistry , fluorescence , optoelectronics , singlet state , physics , quantum mechanics , nuclear physics , excited state
It is an enormous challenge to achieve highly efficient organic room‐temperature phosphorescence (RTP) with a long lifetime. We demonstrate that, by bridging the carbazole and halogenated phenyl ring with a methylene linker, RTP phosphors CzBX (X=Cl, Br) present high phosphorescence efficiency ( Φ Ph ). A Φ Ph up to 38 % was obtained for CzBBr with a lifetime of 220 ms, which is much higher than that of compounds CzPX (X=Cl, Br) with a C−N bond as a linker ( Φ Ph <1 %). Single‐crystal analysis and theoretical calculations revealed that, in the crystal phase, intermolecular π‐Br interactions accelerate the intersystem crossing process, while tetrahedron‐like structures induced by sp 3 methylene linkers restrain the nonradiative decay channel, leading to the high phosphorescence efficiency in CzBBr. This research paves a new road toward highly efficient and long‐lived RTP materials with potential applications in anti‐counterfeiting or data encryption.