On the orientation of benzene adsorbed on Cu{110}

The orientation of benzene on Cu{110} has been determined at low and high coverages by angle-resolved photoemission and high resolution electron energy loss spectroscopy. The results clearly indicate that the molecular plane is substantially tilted with respect to the metal surface at all coverages, in disagreement with an earlier NEXAFS investigation. These findings are discussed in the light of the previously reported reaction kinetics of acetylene trimerisation over Cu{110} and comparison is drawn with the same reaction over Pd(111).