How Symmetry Governs the Dihedral Angle Dependence of Intermolecular Spin-Orbit Coupling
Abstract
Spin-orbit, charge-transfer intersystem crossing (SOCT-ISC) allows for the efficient production of triplet excited states in donor-acceptor (DA) dyads without the involvement of heavy atoms, for use in a myriad of technologies. This process is commonly believed to proceed optimally when the dihedral angle between donor and acceptor moieties is orthogonal. Here, we challenge this idea through a theoretical study unveiling a scenario where spin-orbit couplings (SOCs) are minimized under orthogonal conditions. This scenario is rationalized based on an analysis of the structure-imposed symmetry properties of the involved singlet and triplet states. Notably, in this scenario, finite SOCs demand oblique orientation angles, which in turn requires molecular chirality, suggesting chirality to be a prerequisite for activating the involved SOC pathways.
Keywords
Cite
@article{arxiv.2603.28961,
title = {How Symmetry Governs the Dihedral Angle Dependence of Intermolecular Spin-Orbit Coupling},
author = {Antonio J. Garzon-Ramirez and Connor K. Terry Weatherly and Kyle T. Kairys and Michael R. Wasielewski and Roel Tempelaar},
journal= {arXiv preprint arXiv:2603.28961},
year = {2026}
}
Comments
8 pages, 4 figures