title: Temperature dependence of the 1,6-diphenyl-1,3,5-hexatriene triplet lifetime in solution and theoretical evaluation of triplet conformer interconversion.
abstract: The 1,6-diphenyl-1,3,5-hexatriene (DPH) triplet decay rate constant in degassed benzene is strongly temperature-dependent. Photostationary states for the fluorenone-sensitized photoisomerization of DPH in degassed methylcyclohexane (MCH) favor the all-trans isomer and become richer in the cis isomers as the temperature is increased. The results are interpreted in terms of competing decays from equilibrated triplet conformers on the basis of the experimentally derived DPH triplet potential energy surface [Saltiel, J.; Crowder, J. M.; Wang, S. J. Am. Chem. Soc. 1999, 121, 895 902; 5352]. Calculated geometries and energy differences [B3LYP/6-311+G(d,p)] are consistent with the experimental model.
authors.affiliation: Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, USA. saltiel@chem.fsu.edu
authors.forename: Jack
authors.initials: J
authors.lastname: Saltiel
authors.forename: Rodney
authors.initials: R
authors.lastname: Klima
authors.forename: L J
authors.initials: LJ
authors.lastname: van de Burgt
authors.forename: Shujun
authors.initials: S
authors.lastname: Wang
authors.forename: Olga
authors.initials: O
authors.lastname: Dmitrenko