A long excited state lifetime is a desirable quality of photocatalysts because it enables a higher probability of energy or electron transfer from the photocatalyst to a substrate. Yet, achieving a long lifetime in organic (metal-free) catalysts is challenged by competing rapid nonradiative relaxation from excited states and relatively slow intersystem crossing into long-lived states with different spin multiplicity. Here, we propose an intersystem crossing mechanism in heavy-metal free photocatalyst that results from reorganization of a dihedral angle between moieties. The relaxation of orthogonality of the dihedral angle and increasing the orbital overlap between the two components of the molecule changes the coupling between the configurations of singlet and triplet states, which in turn results in larger spin orbit coupling between the two manifolds as the molecule twists. We predict that this enables intersystem crossing to outcompete the singlet state lifetime.
Kim, Hwon and Scholes, Gregory. "Configuration Mixing Upon Reorganization of Dihedral Angle Induces Rapid Intersystem Crossing in Organic Photoredox catalyst." Physical Chemistry Chemical Physics. PCCP, vol. 22, May. 2020. https://doi.org/10.1039/D0CP01911A
Kim, Hwon, and Scholes, Gregory, "Configuration Mixing Upon Reorganization of Dihedral Angle Induces Rapid Intersystem Crossing in Organic Photoredox catalyst," Physical Chemistry Chemical Physics. PCCP 22 (2020), https://doi.org/10.1039/D0CP01911A
@article{osti_1630695,
author = {Kim, Hwon and Scholes, Gregory},
title = {Configuration Mixing Upon Reorganization of Dihedral Angle Induces Rapid Intersystem Crossing in Organic Photoredox catalyst},
annote = {A long excited state lifetime is a desirable quality of photocatalysts because it enables a higher probability of energy or electron transfer from the photocatalyst to a substrate. Yet, achieving a long lifetime in organic (metal-free) catalysts is challenged by competing rapid nonradiative relaxation from excited states and relatively slow intersystem crossing into long-lived states with different spin multiplicity. Here, we propose an intersystem crossing mechanism in heavy-metal free photocatalyst that results from reorganization of a dihedral angle between moieties. The relaxation of orthogonality of the dihedral angle and increasing the orbital overlap between the two components of the molecule changes the coupling between the configurations of singlet and triplet states, which in turn results in larger spin orbit coupling between the two manifolds as the molecule twists. We predict that this enables intersystem crossing to outcompete the singlet state lifetime.},
doi = {10.1039/D0CP01911A},
url = {https://www.osti.gov/biblio/1630695},
journal = {Physical Chemistry Chemical Physics. PCCP},
issn = {ISSN PPCPFQ},
volume = {22},
place = {United States},
publisher = {Royal Society of Chemistry},
year = {2020},
month = {05}}
USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences & Biosciences Division
Grant/Contract Number:
SC0019370
OSTI ID:
1630695
Alternate ID(s):
OSTI ID: 1632042 OSTI ID: 1756834
Journal Information:
Physical Chemistry Chemical Physics. PCCP, Journal Name: Physical Chemistry Chemical Physics. PCCP Vol. 22; ISSN 1463-9076; ISSN PPCPFQ
Journal Article
·
Tue Sep 03 20:00:00 EDT 2024
· Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory
·OSTI ID:2460473