Electronic structure of norbornadiene and quadricyclane

Abstract:

The ground and excited state electronic structure of the molecular photoswitches quadricyclane and norbornadiene is examined qualitatively and quantitatively. A new custom basis set is introduced, optimised for efficient yet accurate calculations. A number of advanced multi-configurational and multi-reference electronic structure methods are evaluated, identifying those sufficiently accurate and efficient to be used in on-the-fly simulations of photoexcited dynamics. The key valence states participating in the isomerisation reaction are investigated, specifically mapping the important S1/S0 conical intersection that governs the non-radiative decay of the excited system. The powerful yet simple three-state valence model introduced here provides a suitable base for future computational exploration of the photodynamics of the substituted molecules suitable for e.g. energy-storage applications.

Additional Resources

DOI: 10.1039/D4CP03960B

Bibtex:

@Article{coo25electronic,
author ="Cooper, Joseph C. and Kirrander, Adam",
title  ="Electronic structure of norbornadiene and quadricyclane",
journal  ="Phys. Chem. Chem. Phys.",
year  ="2025",
volume  ="27",
issue  ="6",
pages  ="3089-3101",
publisher  ="The Royal Society of Chemistry",
doi  ="10.1039/D4CP03960B",
url  ="http://dx.doi.org/10.1039/D4CP03960B",
}