title: Chemiluminescence and Fluorescence States of a Small Model for Coelenteramide and Cypridina Oxyluciferin: A CASSCF/CASPT2 Study.
abstract: Fluorescence and chemiluminescence phenomena are often confused in experimental and theoretical studies on the luminescent properties of chemical systems. To establish the patterns that distinguish both processes, the fluorescent and chemiluminescent states of 2-acetamido-3-methylpyrazine, which is a small model of the coelenterazine/coelenteramide and Cypridina luciferin/oxyluciferin bioluminescent systems, were characterized by using the complete active space second-order perturbation (CASPT2) method. Differences in geometries and electronic structures among the states responsible for light emission were found. On the basis of the findings, some recommendations for experimental studies on chemiluminescence are suggested, and more appropriate theoretical approaches are proposed.
authors.affiliation: Department of Chemistry-Ångström, Theoretical Chemistry Programme, Uppsala University , P.O. Box 518, S-75120 Uppsala, Sweden.
authors.forename: Daniel
authors.initials: D
authors.lastname: Roca-Sanjuán
authors.affiliation: Department of Chemistry-Ångström, Theoretical Chemistry Programme, Uppsala University , P.O. Box 518, S-75120 Uppsala, Sweden.
authors.forename: Mickael G
authors.initials: MG
authors.lastname: Delcey
authors.affiliation: Molecular Science Institute School of Chemistry, University of the Witwatersrand , PO Wits Johannesburg 2050, South Africa.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Navizet
authors.affiliation: Universités d'Aix-Marseille I, II, et III -CNRS UMR 6264: Laboratoire Chimie Provence, Equipe: Chimie Théorique Faculté de St-Jérome, Case 521, 13397 Marseille Cedex 20, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Ferré
authors.affiliation: Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University , Beijing 100875, China.
authors.forename: Ya-Jun
authors.initials: YJ
authors.lastname: Liu
authors.affiliation: Department of Chemistry-Ångström, Theoretical Chemistry Programme, Uppsala University , P.O. Box 518, S-75120 Uppsala, Sweden.
authors.forename: Roland
authors.initials: R
authors.lastname: Lindh