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Aggregation‐Induced Dual Phosphorescence from ( o ‐Bromophenyl)‐Bis(2,6‐Dimethylphenyl)Borane at Room Temperature
Author(s) -
Wu Zhu,
Dinkelbach Fabian,
Kerner Florian,
Friedrich Alexandra,
Ji Lei,
Stepanenko Vladimir,
Würthner Frank,
Marian Christel M.,
Marder Todd B.
Publication year - 2022
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.202200525
Subject(s) - phosphorescence , intersystem crossing , photochemistry , phosphor , intermolecular force , chemistry , borane , monomer , materials science , molecule , organic chemistry , atomic physics , singlet state , fluorescence , optoelectronics , physics , catalysis , excited state , polymer , quantum mechanics
Designing highly efficient purely organic phosphors at room temperature remains a challenge because of fast non‐radiative processes and slow intersystem crossing (ISC) rates. The majority of them emit only single component phosphorescence. Herein, we have prepared 3 isomers ( o , m , p ‐bromophenyl)‐bis(2,6‐dimethylphenyl)boranes. Among the 3 isomers ( o ‐, m ‐ and p ‐ BrTAB ) synthesized, the ortho ‐one is the only one which shows dual phosphorescence, with a short lifetime of 0.8 ms and a long lifetime of 234 ms in the crystalline state at room temperature. Based on theoretical calculations and crystal structure analysis of o ‐ BrTAB , the short lifetime component is ascribed to the T 1 M state of the monomer which emits the higher energy phosphorescence. The long‐lived, lower energy phosphorescence emission is attributed to the T 1 A state of an aggregate, with multiple intermolecular interactions existing in crystalline o ‐ BrTAB inhibiting nonradiative decay and stabilizing the triplet states efficiently.