title: Surface reactions of 3-butenenitrile on the Si(001)-2 x 1 surface at room temperature.
abstract: Using a combination of local -- scanning tunneling microscopy -- and spatially integrated, but chemically sensitive probes -- X-ray photoelectron spectroscopy and near edge X-ray absorption fine structure spectroscopy -- we have examined how 3-butenenitrile reacts with the Si(001)-2 x 1 surface at room temperature. Electron spectroscopies indicate three different nitrogen chemical bonds: a Si-C=N-Si bond, a C=C=N cumulative double bond, and a CN moiety datively bonded to a silicon atom. All molecular imprints detected by scanning tunneling microscopy (STM) involve two adjacent silicon dimers in the same row. The three geometries we propose -- a double di-sigma bonding via the CN and the C=C, a cumulative double bond formation associated with alphaC-H bond dissociation, and a di-sigma vinyl bonding plus a CN datively bonded to a silicon atom -- are all compatible with electron spectroscopies and data. Real-time Auger yield kinetic measurements show that the double di-sigma bonding geometry is unstable when exposed to a continuous flux of 3-butenenitrile molecules, as the Si-C=N-Si unit transforms into a CN moiety. A model is proposed to explain this observation.
authors.affiliation: Laboratoire de Chimie Physique Matière et Rayonnement, 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05, France.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Rangan
authors.forename: Fabrice
authors.initials: F
authors.lastname: Bournel
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Gallet
authors.forename: Stefan
authors.initials: S
authors.lastname: Kubsky
authors.forename: Karine
authors.initials: K
authors.lastname: Le Guen
authors.forename: Georges
authors.initials: G
authors.lastname: Dufour
authors.forename: François
authors.initials: F
authors.lastname: Rochet
authors.forename: Fausto
authors.initials: F
authors.lastname: Sirotti
authors.forename: Guido
authors.initials: G
authors.lastname: Piaszenski
authors.forename: Ralf
authors.initials: R
authors.lastname: Funke
authors.forename: Martin
authors.initials: M
authors.lastname: Kneppe
authors.forename: Ulrich
authors.initials: U
authors.lastname: Köhler