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Intramolecular Singlet Fission in an Antiaromatic Polycyclic Hydrocarbon
Author(s) -
Wu Yishi,
Wang Yuancheng,
Chen Jianwei,
Zhang Guanxin,
Yao Jiannian,
Zhang Deqing,
Fu Hongbing
Publication year - 2017
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201704668
Subject(s) - intramolecular force , singlet fission , antiaromaticity , chromophore , exciton , intermolecular force , singlet state , chemistry , triplet state , chemical physics , population , photochemistry , molecule , atomic physics , physics , stereochemistry , excited state , condensed matter physics , organic chemistry , aromaticity , demography , sociology
Singlet fission (SF), in which one singlet exciton (S 1 ) splits into two triplets (T 1 ) on adjacent molecules through a correlated triplet‐pair 1 (TT) state, requires precise but difficult tuning of exciton energetics and intermolecular electronic couplings in the solid state. Antiaromatic 4nπ dibenzopentalenes (DPs) are demonstrated as a new class of single‐chromophore‐based intramolecular SF materials that exhibit an optically allowed S 2 state with E(S 2 )>2×E(T 1 ) and an optically forbidden S 1 state. Ultrafast population transfer from a high‐lying S 2 state to a 1 (TT) state was observed in monomeric solution of styryl‐substituted DP (SDP) on a sub‐picosecond timescale. There is evidence of exciton diffusion (ED) of the 1 (TT) state to yield two individual long‐lived triplets in SDP thin film. The overall triplet yield via intramolecular SF and subsequent triplet‐pair diffusion can be as high as 142±10 % in thin film.