title: The first photocrystallographic evidence for light-induced metastable linkage isomers of ruthenium sulfur dioxide complexes.
abstract: Light-induced metastable linkage isomers of trans-[Ru(NH(3))(4)Cl(SO(2))]Cl and trans-[Ru(NH(3))(4)(H(2)O)(SO(2))](C(6)H(5)SO(3))(2) have been identified for the first time using photocrystallographic methods. In both linkage isomers the SO(2) ligand is side bound, but the Ru-O and Ru-S distances are considerably longer and almost equal in the trans-H(2)O isomer. DFT calculations confirm that both isomers correspond to minima on the ground-state potential energy surface and also predict the existence of a second oxygen-bound isomer for both compounds. The decay of the light-induced species has been studied by both DSC and IR. Activation energies for the thermal back-reaction, as derived from the temperature-dependent disappearance of light-induced IR bands, are 50.0 and 58.4 kJ/mol for the two isomers, which is larger than the corresponding numbers for photoinduced side-bound nitrosyl linkage isomers.
authors.affiliation: Chemistry Department, State University of New York at Buffalo, Buffalo, New York 14260, USA.
authors.forename: Andrey Yu
authors.initials: AY
authors.lastname: Kovalevsky
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Bagley
authors.forename: Philip
authors.initials: P
authors.lastname: Coppens