title: Quantum chemical study of the photocoloration reaction in the napthoxazine series.
abstract: Ab initio and semiempirical quantum mechanical calculations were performed to study the electronic spectra of spiroxazine photochromic compounds as well as the corresponding photoisomers. Ground-state geometries were optimized based on density functional theory (DFT). Excitation energies of the different forms were calculated using the time-dependent density functional theory (TD-DFT) method. Semiempirical calculations including configuration interactions were performed to detail the mechanism of ring opening in excited states. On the basis of the obtained potential energy profile, a complete mechanism of photocoloration able to clarify some experimental findings is provided. A correlation of the experimental quantum yield of photocoloration with the calculated properties as a function of substituent effects is proposed.
authors.affiliation: Laboratoire Interfaces, Traitements, Organisation et DYnamique des Systèmes, ITODYS, Université de Paris 7-Denis Diderot, UMR 7086, 1 rue Guy de la Brosse 75005 Paris, France. maurel@paris6.jussieu.fr
authors.forename: F
authors.initials: F
authors.lastname: Maurel
authors.forename: J
authors.initials: J
authors.lastname: Aubard
authors.forename: P
authors.initials: P
authors.lastname: Millie
authors.forename: J P
authors.initials: JP
authors.lastname: Dognon
authors.forename: M
authors.initials: M
authors.lastname: Rajzmann
authors.forename: R
authors.initials: R
authors.lastname: Guglielmetti
authors.forename: A
authors.initials: A
authors.lastname: Samat