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A Pure‐Red Doublet Emission with 90 % Quantum Yield: Stable, Colorless, Iodinated Triphenylmethane Solid
Author(s) -
Liu ChengHao,
Hamzehpoor Ehsan,
SakaiOtsuka Yoko,
Jadhav Thaksen,
Perepichka Dmitrii F.
Publication year - 2020
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202009867
Subject(s) - quantum yield , triphenylmethane , photoluminescence , photochemistry , excited state , luminescence , chemistry , yield (engineering) , materials science , atomic physics , fluorescence , optoelectronics , optics , organic chemistry , physics , metallurgy
Red luminescence is found in off‐white tris(iodoperchlorophenyl)methane ( 3I‐PTM H ) crystals which is characterized by a high photoluminescence quantum yield (PLQY 91 %) and color purity (CIE coordinates 0.66, 0.34). The emission originates from the doublet excited state of the neutral radical 3I‐PTM R , which is spontaneously formed and becomes embedded in the 3I‐PTM H matrix. The radical defect can also be deliberately introduced into 3I‐PTM H crystals which maintain a high PLQY with up to 4 % radical concentration. The immobilized iodinated radical demonstrates excellent photostability (estimated half‐life >1 year under continuous irradiation) and intriguing luminescent lifetime (69 ns). TD‐DFT calculations demonstrate that electron‐donating iodine atoms accelerate the radiative transition while the rigid halogen‐bonded matrix suppresses the nonradiative decay.