TY - JOUR
T1 - Intramolecular Noncovalent Interactions Facilitate Thermally Activated Delayed Fluorescence (TADF)
AU - Chen, Xian Kai
AU - Bakr, Brandon W.
AU - Auffray, Morgan
AU - Tsuchiya, Youichi
AU - Sherrill, C. David
AU - Adachi, Chihaya
AU - Bredas, Jean Luc
PY - 2019/6/20
Y1 - 2019/6/20
N2 - In the conventional molecular design of thermally activated delayed fluorescence (TADF) organic emitters, simultaneously achieving a fast rate of reverse intersystem crossing (RISC) from the triplet to the singlet manifold and a fast rate of radiative decay is a challenging task. A number of recent experimental data, however, point to TADF emitters with intramolecular π-πinteractions as a potential pathway to overcome the issue. Here, we report a comprehensive investigation of TADF emitters with intramolecular π···πor lone-pair···πnoncovalent interactions. We uncover the impact of those intramolecular noncovalent interactions on the TADF properties. In particular, we find that folded geometries in TADF molecules can trigger lone-pair···πinteractions, introduce a n → π∗ character of the relevant transitions, enhance the singlet-triplet spin-orbit coupling, and ultimately greatly facilitate the RISC process. This work provides a robust foundation for the molecular design of a novel class of highly efficient TADF emitters in which intramolecular noncovalent interactions play a critical function.
AB - In the conventional molecular design of thermally activated delayed fluorescence (TADF) organic emitters, simultaneously achieving a fast rate of reverse intersystem crossing (RISC) from the triplet to the singlet manifold and a fast rate of radiative decay is a challenging task. A number of recent experimental data, however, point to TADF emitters with intramolecular π-πinteractions as a potential pathway to overcome the issue. Here, we report a comprehensive investigation of TADF emitters with intramolecular π···πor lone-pair···πnoncovalent interactions. We uncover the impact of those intramolecular noncovalent interactions on the TADF properties. In particular, we find that folded geometries in TADF molecules can trigger lone-pair···πinteractions, introduce a n → π∗ character of the relevant transitions, enhance the singlet-triplet spin-orbit coupling, and ultimately greatly facilitate the RISC process. This work provides a robust foundation for the molecular design of a novel class of highly efficient TADF emitters in which intramolecular noncovalent interactions play a critical function.
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U2 - 10.1021/acs.jpclett.9b01220
DO - 10.1021/acs.jpclett.9b01220
M3 - Article
C2 - 31141375
AN - SCOPUS:85067671942
VL - 10
SP - 3260
EP - 3268
JO - Journal of Physical Chemistry Letters
JF - Journal of Physical Chemistry Letters
SN - 1948-7185
IS - 12
ER -