The adsorption of nickelocene - Part 1: molecular bonding on Ag(100)

The molecular adsorption and desorption of nickelocene, Ni(C5H5)(2), on Ag(100) have been studied by both angle-resolved photoemission and thermal desorption. Photoemission results indicate that the initially adsorbed surface species closely resemble that of molecular nickelocene. The molecular axis is not along the surface normal, as determined by angle-resolved photoemission and angle-resolved thermal desorption spectroscopy. This is a different bonding orientation than that adopted by molecular ferrocene on Ag(100). The molecular nickelocene desorption energies resemble those observed for ferrocene on Ag(100) but are complicated by multiple chemisorption states and steric effects in the desorption process. Nickelocene is unusual in that the molecular orientation is seen to affect the angular dependence of molecular desorption. (C) 1997 Elsevier Science B.V.