title: Theoretical studies of conjugation effects on excited state intramolecular hydrogen-atom transfer reactions in model systems.
abstract: Intramolecular hydrogen-atom transfer dependence on electronic conjugation of curcumin and related molecular models in the ground state and 1pipi* excited state are computationally studied at the first-principles electronic structure level. The larger, more conjugated, systems exhibit a lower reaction barrier in the ground state but a higher barrier in the excited state. This is associated with a smaller increase in the conjugation upon excitation in the larger systems. Our studies provide a detailed description and analysis of these energy trends as well as an insight into the physical nature of the intramolecular hydrogen-atom transfer reactions.
authors: Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, USA.
authors: Carlos R
authors: CR
authors: Baiz
authors: Barry D
authors: BD
authors: Dunietz
mesh_terms: D001703:Biophysics / Q000379:methods; D002627:Chemistry, Physical / Q000379:methods; D004583:Electrons; D006859:Hydrogen / Q000737:chemistry; D006860:Hydrogen Bonding; D008956:Models, Chemical; D008958:Models, Molecular; D008962:Models, Theoretical; D008968:Molecular Conformation; D015394:Molecular Structure; D011522:Protons; D012984:Software
chemical_list: D011522:Protons; D006859:Hydrogen