title: Excited-state hydroxide ion transfer from a model xanthenol photobase.
abstract: This article reports a study of excited-state hydroxide ion release from a model xanthenol photobase, XanOH. The driving force for the reaction was tuned using solvent mixtures with varying water/acetonitrile ratios, and the kinetics of the reaction was monitored using ultrafast pump-probe spectroscopy. The intrinsic barrier for the heterolysis was evaluated using Marcus and bond-energy bond-order (BEBO) models. The obtained value (ΔG(o)(#) = 10.17-10.80 kcal/mol) is significantly higher than the intrinsic barriers found for the proton release from previously studied photoacids. These results were discussed in terms of the difference in structures of solvated H(+) and OH(-) ions.
authors.affiliation: Department of Chemistry and Center for Photochemical Sciences, Bowling Green State University , Bowling Green, Ohio 43403, United States.
authors.forename: Yun
authors.initials: Y
authors.lastname: Xie
authors.forename: Hoi Ling
authors.initials: HL
authors.lastname: Luk
authors.forename: Xin
authors.initials: X
authors.lastname: Yang
authors.forename: Ksenija D
authors.initials: KD
authors.lastname: Glusac
mesh_terms: D006878:Hydroxides / Q000737:chemistry*; D007700:Kinetics; D013816:Thermodynamics; D014966:Xanthenes / Q000737:chemistry*
chemical_list: D006878:Hydroxides; D014966:Xanthenes; C031356:hydroxide ion