TY - JOUR
T1 - Dual Fluorescence of Octatetraene Hints at a Novel Type of Singlet-to-Singlet Thermally Activated Delayed Fluorescence Process
AU - Park, Woojin
AU - Shen, Jun
AU - Lee, Seunghoon
AU - Piecuch, Piotr
AU - Joo, Taiha
AU - Filatov(gulak), Michael
AU - Choi, Cheol Ho
N1 - Publisher Copyright:
© 2022 American Chemical Society.
PY - 2022/9/8
Y1 - 2022/9/8
N2 - A novel type of singlet-to-singlet thermally activated delayed fluorescence (STS-TADF) from the optically bright 11Bu+ and dark 21Ag- states of octatetraene is proposed based on state-of-the-art ab initio simulations. The new phenomenon bears similarity with TADF, the key difference being that in the normal TADF the emissive state is repopulated from a nearby triplet, whereas in STS-TADF it occurs from a nearby dark singlet state (21Ag-). The nonadiabatic populations of the bright and dark singlet excited states are dynamically redistributed through a conical intersection mediated by an ultrafast skeleton C-C stretching vibration, establishing a steady state for a sufficiently long time to undergo radiative decay. The steady state manifests itself in the experimentally observed dual fluorescence. It is expected that the STS-TADF can be observed in other π-conjugated chromophores as well.
AB - A novel type of singlet-to-singlet thermally activated delayed fluorescence (STS-TADF) from the optically bright 11Bu+ and dark 21Ag- states of octatetraene is proposed based on state-of-the-art ab initio simulations. The new phenomenon bears similarity with TADF, the key difference being that in the normal TADF the emissive state is repopulated from a nearby triplet, whereas in STS-TADF it occurs from a nearby dark singlet state (21Ag-). The nonadiabatic populations of the bright and dark singlet excited states are dynamically redistributed through a conical intersection mediated by an ultrafast skeleton C-C stretching vibration, establishing a steady state for a sufficiently long time to undergo radiative decay. The steady state manifests itself in the experimentally observed dual fluorescence. It is expected that the STS-TADF can be observed in other π-conjugated chromophores as well.
UR - http://www.scopus.com/inward/record.url?scp=85137294648&partnerID=8YFLogxK
U2 - 10.1021/acs.jpcc.2c04105
DO - 10.1021/acs.jpcc.2c04105
M3 - Article
AN - SCOPUS:85137294648
SN - 1932-7447
VL - 126
SP - 14976
EP - 14985
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 35
ER -