Beyond Jablonski diagrams in organic systems: ab initio studies of substituted benzene derivatives

Identifier:  TDX:989

Handle: https://hdl.handle.net/20.500.11797/TDX989

Authors:  Segado Centellas, Mireia

Abstract:
This thesis is focused on theoretical study of several photosensitive molecular systems. It covers the study of some frequently encountered processes: photosensititzation and Intramolecular Charge Transfer (ICT). The photosensititzation is a process where a light-absorbing photosensititzer (PS) activates reactions in a substrate that otherwise would not take place. Intramolecular charge transfer is the process related with the transference of charge from different regions of the same molecule, one donor and other acceptor. These studies are addressed by theoretical study using ab intio methods, assessing the nature of the excited states involved, the geometries and energies of the species formed and the mechanism that lead to photochemical transformation and photophysical processes. In the first case photosensititzation process by means of Phenalenone is studied. In the case of the ICT process two families are studied: Aminobenzonitriles and Aminopyrimidines. Possible ICT states, non-adiabatic and adiabatic pathways that populate different lowest in energy minima are characterized.