title: Subnanosecond isomerization in an osmium-dimethyl sulfoxide complex.
abstract: We report the structure, spectroscopy, and electrochemistry of cis-[Os(bpy)(2)(DMSO)(2)](OTf)(2), where bpy is 2,2'-bipyridine, DMSO is dimethyl sulfoxide, and OTf is trifluoromethanesulfonate. Electrochemical measurements are consistent with S-to-O isomerization following the oxidation of Os(2+) (1.8 V vs Ag/AgCl). Visible irradiation of the metal-to-ligand charge-transfer transition (355 nm) of [Os(bpy)(2)(DMSO)(2)](2+) in the solid state and solution yields an emissive S-bonded excited state and S-to-O excited-state isomerization on a subnanosecond time scale. These results and a comparison to the nonphotoactive [Os(bpy)(2)Cl(DMSO)](+) are discussed.
authors.affiliation: Department of Chemistry and Biochemistry, Ohio University, Athens, 45701, USA.
authors.forename: Nicholas V
authors.initials: NV
authors.lastname: Mockus
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Petersen
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Rack