title: Bond-Selective and Mode-Specific Dissociation of CH3D and CH2D2 on Pt(111).
abstract: Infrared laser excitation of partially deuterated methanes (CH3D and CH2D2) in a molecular beam is used to control their dissociative chemisorption on a Pt(111) single crystal and to determine the quantum state-resolved dissociation probabilities. The exclusive detection of C-H cleavage products adsorbed on the Pt(111) surface by infrared absorption reflection spectroscopy indicates strong bond selectivity for both methane isotopologues upon C-H stretch excitation. Furthermore, the dissociative chemisorption of both methane isotopologues is observed to be mode-specific. Excitation of symmetric C-H stretch modes produces a stronger reactivity increase than excitation of the antisymmetric C-H stretch modes, whereas bend overtone excitation has a weaker effect on reactivity. The observed mode specificity and bond selectivity are rationalized by the sudden vector projection model in terms of the overlap of the reactant's normal mode vectors with the reaction coordinate at the transition state.
authors.affiliation: Laboratoire de Chimie Physique Moléculaire, Ecole Polytechnique Fédérale de Lausanne , Lausanne 1015, Switzerland.
authors.forename: P Morten
authors.initials: PM
authors.lastname: Hundt
authors.affiliation: Laboratoire de Chimie Physique Moléculaire, Ecole Polytechnique Fédérale de Lausanne , Lausanne 1015, Switzerland.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Ueta
authors.affiliation: Laboratoire de Chimie Physique Moléculaire, Ecole Polytechnique Fédérale de Lausanne , Lausanne 1015, Switzerland.
authors.forename: Maarten E
authors.initials: ME
authors.lastname: van Reijzen
authors.affiliation: Department of Chemistry and Chemical Biology, University of New Mexico , Albuquerque, New Mexico 87131, United States.
authors.forename: Bin
authors.initials: B
authors.lastname: Jiang
authors.affiliation: Department of Chemistry and Chemical Biology, University of New Mexico , Albuquerque, New Mexico 87131, United States.
authors.forename: Hua
authors.initials: H
authors.lastname: Guo
authors.affiliation: Laboratoire de Chimie Physique Moléculaire, Ecole Polytechnique Fédérale de Lausanne , Lausanne 1015, Switzerland.
authors.forename: Rainer D
authors.initials: RD
authors.lastname: Beck