Datensatz

Zusammenfassung

Photoelectron diffraction in the scanned energy mode has been used to determine the structure of benzene adsorbed on to an Ni{111} surface. In the disordered phase at low coverage the molecule is centered over a bridge site with the C-C bonds oriented in the 〈211〉 directions, but in the ordered overlayer at saturation coverage the hcp threefold symmetric hollow site is occupied with the C-C bonds oriented in the 〈110〉 directions. The molecular planes are situated 1.92(±0.05) Å and 1.91(±0.04) Å, respectively, above the Ni atoms which form each adsorption site. There is no significant distortion of the benzene ring. The results are compared with photoemission measurements and quantum chemical calculations.