title: The low-energy unimolecular reaction rate constants for the gas phase, Ni+-mediated dissociation of the C-C sigma bond in acetone.
abstract: The time dependence of the gaseous unimolecular decomposition of the jet-cooled adduct ion, Ni+-OC(CH3)2, was monitored through selective detection of the Ni+CO fragment ion. Various resolved amounts of energy in the range 15600-18800 cm(-1) were supplied to initiate the dissociation reaction through absorption of laser photons by the title molecular complex. First-order rate constants, k(E), ranged from 113000 to 55000 s(-1) and decreased with decreasing amounts of internal excitation. The energy used to initiate the reaction is well below that required to fragment C-C sigma bonds and indicates the necessity of the Ni+ cation to induce bond activation and fragmentation. These measurements are carried out in a unique apparatus and represent the first direct kinetic study of such catalytic type reactions.
authors.affiliation: Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, Texas 76798-7348, USA.
authors.forename: Vanessa A
authors.initials: VA
authors.lastname: Castleberry
authors.forename: S Jason
authors.initials: SJ
authors.lastname: Dee
authors.forename: Otsmar J
authors.initials: OJ
authors.lastname: Villarroel
authors.forename: Ivanna E
authors.initials: IE
authors.lastname: Laboren
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Frey
authors.forename: Darrin J
authors.initials: DJ
authors.lastname: Bellert