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
N1 - Funding Information:
X.K.C. and J.L.B. acknowledge funding of their TADF research from the Georgia Institute of Technology and the Department of Energy (DE-EE0008205); they are also grateful to Kyulux for generous support of their activities. B.W.B. and C.D.S. acknowledge financial support from the U.S. National Science Foundation through grant CHE-1566192. The work performed at Kyushu University was supported by the Japan Science and Technology Agency (JST), ERATO, Adachi Molecular Exciton Engineering Project, under JST ERATO Grant Number JPMJER1305, Japan, and JSPS KAKENHI Grant Number 17H01232.
Publisher Copyright:
© 2019 American Chemical Society.
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 -