title: Uracil on Cu(110): a quantitative structure determination by energy-scanned photoelectron diffraction.
abstract: The local adsorption site of the nucleobase uracil on Cu(110) has been determined quantitatively by energy-scanned photoelectron diffraction (PhD). Qualitative inspection of the O 1s and N 1s soft x-ray photoelectron spectra, PhD modulation spectra, and O K-edge near-edge x-ray adsorption fine structure indicate that uracil bonds to the surface through its nitrogen and oxygen constituent atoms, each in near atop sites, with the molecular plane essentially perpendicular to surface and aligned along the close packed [110] azimuth. Multiple scattering simulations of the PhD spectra confirm and refine this geometry. The Cu-N bondlength is 1.96 ± 0.04 Å, while the Cu-O bondlengths of the two inequivalent O atoms are 1.93 ± 0.04 Å and 1.96 ± 0.04 Å, respectively. The molecule is twisted out of the [110]direction by 11 ± 5°.
authors: University of Warwick, Coventry, CV4 7AL, United Kingdom.
authors: D A
authors: DA
authors: Duncan
authors: W
authors: W
authors: Unterberger
authors: D
authors: D
authors: Kreikemeyer-Lorenzo
authors: D P
authors: DP
authors: Woodruff
mesh_terms: D000327:Adsorption; D003300:Copper / Q000737:chemistry*; D008958:Models, Molecular; D014498:Uracil / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D014498:Uracil; D003300:Copper