Photophysical Deactivation Mechanisms of the Pyrimidine Analogue 1-Cyclohexyluracil.

ABSTRACT: The photophysical relaxation mechanisms of 1-cyclohexyluracil, in vacuum and water, were investigated by employing the Multi-State CASPT2 (MS-CASPT2, Multi-State Complete Active-Space Second-Order Perturbation Theory) quantum chemical method and Dunning's cc-pVDZ basis sets. In both environments, our results suggest that the primary photophysical event is the population of the S11(ππ*) bright state. Afterwards, two likely deactivation pathways can take place, which is sustained by linear interpolation in internal coordinates defined via Z-Matrix scans connecting the most important characteristic points. The first one (Route 1) is the same relaxation mechanism observed for uracil, its canonical analogue, i.e., internal conversion to the ground state through an ethylenic-like conical interse

SUBMITTER: Valverde D 

PROVIDER: S-EPMC8434193 | biostudies-literature | 2021 Aug

REPOSITORIES: biostudies-literature