title: Selective binding of the cyano group in acrylonitrile adsorption on Si(100)-2 x 1.
abstract: The covalent binding of acrylonitrile (CH(2)=CH-C triple bond N) and the formation of a C=C-C=N structure on Si(100) have been investigated using high-resolution electron energy loss spectroscopy (HREELS), X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), and density functional theory (DFT) calculations. For chemisorbed acrylonitrile, the absence of nu(C triple bond N) at 2245 cm(-1) and the appearance of nu(C=N) at 1669 cm(-1) demonstrate that the cyano group directly participates in the interaction with Si(100), which is further supported by XPS and UPS observations. Our experimental results and DFT calculations unambiguously demonstrate a [2 + 2] cycloaddition mechanism for acrylonitrile chemisorption on Si(100) through the binding of C triple bond N to Si dimers. The resulting chemisorbed monolayer with a C=C-C=N skeleton can serve as a precursor for further chemical syntheses of multilayer organic thin films in a vacuum and surface functionalization for in situ device fabrication.
authors.affiliation: Department of Chemistry, National University of Singapore, 10 Kent Ridge, Singapore 119260.
authors.forename: F
authors.initials: F
authors.lastname: Tao
authors.forename: W S
authors.initials: WS
authors.lastname: Sim
authors.forename: G Q
authors.initials: GQ
authors.lastname: Xu
authors.forename: M H
authors.initials: MH
authors.lastname: Qiao