J. Phys. IV France 7 (1997) C2-537-C2-538
Identification of Mono- and Bidentate Carboxylate Surface Species on Cu(111) using X-Ray Absorption SpectroscopyA. Schertel, Ch. Wöll and M. Grunze
Angewandte Physikalische Chemie, Im Neuenheimer Feld 253, 69120 Heidelberg, Germany
In order to identify the nature of the bond which is formed when anhydride containing molecules such as pyromellitic dianhydride (PMDA) react with a Cu surface we have carried out measurements using x-ray absorption spectroscopy (NEXAFS) at the Cls and Ols edges. By comparing to reference spectra for benzoic acid bound to Cu surfaces the position of the resonances in NEXAFS-spectra for monolayers of PMDA on a Cu(111)-substrate can be shown to be fully consistent with the presence of a bidentate surface species. Evidence is provided that monodentate species show a characteristic shift of the Cls-πCO-excitation to 287.6 eV (from 288.05 eV for the bidentate species).
© EDP Sciences 1997