title: Thermal Activation of Methane by [HfO](.+) and [XHfO](+) (X=F, Cl, Br, I) and the Origin of a Remarkable Ligand Effect.
abstract: The thermal reactions of methane with [HfO](.+) and [XHfO](+) (X=F, Cl, Br, I) were investigated by using FT-ICR mass spectrometry complemented by high-level quantum chemical calculations. Surprisingly, in contrast to the inertness of [HfO](.+) towards methane, the closed-shell oxide ions [XHfO](+) (X=F, Cl, Br) activate the H3 C-H bond to form the insertion products [Hf(X)(OH)(CH3 )](+) . The possible origin of this remarkable ligand effect is discussed.
authors.affiliation: Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 135, 10623, Berlin, Germany.
authors.forename: Shaodong
authors.initials: S
authors.lastname: Zhou
authors.affiliation: Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 135, 10623, Berlin, Germany.|Institute of Theoretical Chemistry, Jilin University, Changchun, 130023, P.R. China.
authors.forename: Jilai
authors.initials: J
authors.lastname: Li
authors.affiliation: Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 135, 10623, Berlin, Germany.
authors.forename: Maria
authors.initials: M
authors.lastname: Schlangen
authors.affiliation: Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 135, 10623, Berlin, Germany. helmut.schwarz@tu-berlin.de.
authors.forename: Helmut
authors.initials: H
authors.lastname: Schwarz
keywords: closed-shell metal-oxide clusters; gas-phase reactions; ligand effects; methane activation; quantum chemical calculations