title: Rate-limiting step in the low-energy unimolecular decomposition reaction of Ni+* acetone into Ni+CO + ethane.
abstract: Rate constants for the low-energy Ni(+)-assisted C-C bond cleavage reaction of deuterium-labeled acetone have been acquired under jet-cooled conditions in the gas phase. The energies used to initiate the dissociative reactions of the precursor complex ion Ni(+)(d(6)-Ac) are well below that required to cleave C-C sigma-bonds in isolated organic molecules. The rate constants are compared to those acquired previously for the lighter Ni(+)(h(6)-Ac) isotope and result in a substantial kinetic isotope effect (k(H)/k(D) approximately 5.5). Arguments are made that implicate isomerization leading to C-C bond coupling as the rate-limiting step (not C-C sigma-bond activation) in the dissociative reaction.
authors.affiliation: Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, Texas 76798-7348, USA.
authors.forename: S Jason
authors.initials: SJ
authors.lastname: Dee
authors.forename: Vanessa A
authors.initials: VA
authors.lastname: Castleberry
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: Daniel
authors.initials: D
authors.lastname: Ashley
authors.forename: Darrin J
authors.initials: DJ
authors.lastname: Bellert