title: Density functional theory study of 1,2-dioxetanone decomposition in condensed phase.
abstract: The decomposition of 1,2-dioxetanone into a CO(2) molecule and into an excited state formaldehyde molecule was studied in condensed phase, using a density functional theory approach. Singlet and triplet ground and excited states were all included in the calculations. The calculations revealed a novel mechanism for the chemiluminescence of this compound. The triplet excitation can be explained by two intersystem crossings (ISCs) with the ground state, while the singlet excitation can be accounted by an ISC with the triplet state. The experimentally verified small excitation yield can then be explained by the presence of an energy barrier present in the potential energy surface of the triplet excited state, which will govern both triplet and singlet excitation. It was also found that the triplet ground state interacts with both the triplet excited and singlet ground states. A MPWB1K/mPWKCIS approach provided results in agreement with the existent literature.
authors.affiliation: Departamento de Química e Bioquímica, Centro de Investigação em Química, Faculdade de Ciências da Universidade do Porto, Campo Alegre 687, 4169-007 Porto, Portugal.
authors.forename: Luís
authors.initials: L
authors.lastname: Pinto da Silva
authors.forename: Joaquim C G
authors.initials: JC
authors.lastname: Esteves da Silva
mesh_terms: D006573:Heterocyclic Compounds, 1-Ring / Q000737:chemistry*; D015394:Molecular Structure; D011789:Quantum Theory
chemical_list: D006573:Heterocyclic Compounds, 1-Ring; C541697:dioxetanone