A theoretical perspective on photoinduced reactions - based on quantum chemical models and non-adiabatic molecular dynamics

Abstract: The broad range of applications for photochemical reactions is the result of light-matter interaction at the electronic level. The diverse application of photochemistry in various fields, including photovoltaic materials, molecular switches, and biological systems are due to electronic and structural transformations induced by photoexcitation as well as molecular alteration due to electron and charge transfer. An improved understanding of these photochemical events is dependent on the fundamental theoretical evaluation, to model and analyze the ultrafast processes. The studies discussed in this thesis explore such theoretical implementation in two different frontiers.In the first study, dynamic simulations are performed to model the light-induced bond dissociation of phenyl azide. The surface hopping formalism, implemented under the semiclassical molecular dynamics approach helped in tracing the time evolution of the electronic and structural levels, involved in the photodissociation. In the second study, the time-dependent density functional theory has been applied to generate XA spectra of imidazole solutions. The theoretical assessments support experimental measurements and provide more insight into the core excitations and structural influence on the absorption spectra.