title: Photoinduced processes in dipyrrolyl-perfluoro-cyclopentenes.
abstract: The photobehavior of five photochromic dipyrrolyl-perfluoro-cyclopentenes was studied by steady state and time-resolved absorption spectroscopy. The quantum yields of the UV-photoinduced ring-closing reaction (coloration) and the visible-stimulated cycloreversion reaction (bleaching) were measured. Kinetic and thermodynamic parameters of thermal bleaching were also determined. Nanosecond time-resolved experiments showed formation of a transient, which was not a precursor of the reaction photoproduct. This transient was tentatively assigned to a radical cation formed by direct photoionization through a short-lived triplet state. The nature of the transient species was supported by photoinduced electron transfer to electron acceptors.
authors.affiliation: Università di Perugia, Dipartimento di Chimica, 06123 Perugia, Italy.
authors.forename: Fausto
authors.initials: F
authors.lastname: Ortica
authors.forename: Paola
authors.initials: P
authors.lastname: Smimmo
authors.forename: Ugo
authors.initials: U
authors.lastname: Mazzucato
authors.forename: Gianna
authors.initials: G
authors.lastname: Favaro
authors.forename: Arnault
authors.initials: A
authors.lastname: Heynderickx
authors.forename: Corinne
authors.initials: C
authors.lastname: Moustrou
authors.forename: André
authors.initials: A
authors.lastname: Samat