A Qualitative Approach for Predicting Enhanced Intersystem Crossing in Chromophore-Radical Systems
Abstract
Enhanced Intersystem Crossing (EISC) is an important mechanism that allows for formally forbidden population transfer from the singlet to triplet manifold in chromophore-radical (C-R) systems. We use first order perturbation theory to estimate the likelihood of EISC in various organic C-R molecules. The first order mixing coefficient κ between the states involved in EISC depends on the difference in pairwise exchange interactions between photoexcited chromophore electrons and the radical. Exchange coupling constants were calculated with the Heisenberg-Dirac-Van Vleck Hamiltonian using excited state wave functions and energies obtained from the CASSCF/QD-NEVPT2 calculations. The predictions derived using this framework are in a good agreement with the available experimental data on EISC observed with transient absorption spectroscopy.
Fields of Study & Subjects
Photochemistry and Electron Transfer Studies
Spectroscopy and Quantum Chemical Studies
Machine Learning in Materials Science
Publication details
- Journal / source
- The Journal of Physical Chemistry Letters
- Publisher
- American Chemical Society (ACS)
- Volume
- 17
- Issue
- 12
- Pages
- 3515–3521
- Publication date
- 13 March 2026
- Language
- EN