title: Highly regioselective hydride transfer, oxidative dehydrogenation, and hydrogen-atom abstraction in the thermal gas-phase chemistry of [Zn(OH)](+)/C3H8.
abstract: The thermal reactions of [Zn(OH)](+) with C3H8 have been studied by means of gas-phase experiments and computational investigation. Two types of C-H bond activation are observed in the experiment, and pertinent mechanistic features include inter alia: (i) the metal center of [Zn(OH)](+) serves as active site in the hydride transfer to generate [i-C3H7](+) as major product, (ii) generally, a high regioselectivity is accompanied by remarkable chemoselectivity: for example, the activation of a methyl C-H bond results mainly in the formation of water and [Zn(C3,H7)](+). According to computational work, this ionic product corresponds to [HZn(CH3CH=CH2)](+). Attack of the zinc center at a secondary C-H bond leads preferentially to hydride transfer, thus giving rise to the generation of [i-C3H7](+); (iii) upon oxidative dehydrogenation (ODH), liberation of CH3CH2=CH2 occurs to produce [HZn(H2O)](+). Both, ODH as well as H2O loss proceed through the same intermediate which is characterized by the fact that a methylene hydrogen atom from the substrate is transferred to the zinc and one hydrogen atom from the methyl group to the OH group of [Zn(OH)](+). The combined experimental/computational gas-phase study of C-H bond activation by zinc hydroxide provides mechanistic insight into related zinc-catalyzed large-scale processes and identifies the crucial role that the Lewis-acid character of zinc plays.
authors.affiliation: Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 135, 10623, Berlin. Maria.Schlangen@mail.chem.tu-berlin.de Helmut.Schwarz@tu-berlin.de.
authors.forename: Xiao-Nan
authors.initials: XN
authors.lastname: Wu
authors.forename: Hai-Tao
authors.initials: HT
authors.lastname: Zhao
authors.forename: Jilai
authors.initials: J
authors.lastname: Li
authors.forename: Maria
authors.initials: M
authors.lastname: Schlangen
authors.forename: Helmut
authors.initials: H
authors.lastname: Schwarz