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Persistent Solid‐State Phosphorescence and Delayed Fluorescence at Room Temperature by a Twisted Hydrocarbon
Author(s) -
Salla Cristian A. M.,
Farias Giliandro,
Rouzières Mathieu,
Dechambenoit Pierre,
Durola Fabien,
Bock Harald,
de Souza Bernardo,
Bechtold Ivan H.
Publication year - 2019
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201901672
Subject(s) - phosphorescence , photochemistry , quantum yield , fluorescence , benzene , hydrocarbon , chemistry , excitation , triplet state , materials science , molecule , optics , organic chemistry , physics , engineering , electrical engineering
The dehydrating cyclotrimerization of 1‐tetralone in the presence of titanium tetrachloride at high temperatures leads to homotruxene, a nonplanar arene in which the twist angles between its three outer benzene rings and the central benzene are stabilized by ethylene bridges. This non‐planar configuration allows for pronounced spin–orbit coupling and a high triplet energy, leading to room‐temperature phosphorescence in air with a lifetime of 0.38 s and a quantum yield of 5.6 %, clearly visible to the human eye after switching off the excitation. Triplet–triplet annihilation is found to simultaneously lead to a substantial delayed fluorescence, unprecedented from a pure hydrocarbon at ambient conditions, with a lifetime of 0.11 s.