c-C5H5 on a Ni(111) surface: theoretical study of the adsorption, electronic structure and bonding

E. GERMÁN; S. SIMONETTI; M. E. PRONSATO; G. BRIZUELA; A. JUAN

APPLIED SURFACE SCIENCE

Elsevier B. V.

Año: 2008 vol. 254 p. 5831 - 5836

0169-4332

In the present work the ASED-MO method is applied to study the adsorption of cyclopentadienyl anion on a Ni(1 1 1) surface. The adsorption with the centre of the aromatic ring placed above the hollow position has been identified to be energetically the most favourable. The aromatic ring remains almost flat, the H atoms are tilted 178 away from the metal surface.We modelled the metal surface by a two-dimensional slab of finite thickness, with an overlayer of c-C5H5, one c-C5H5 per nine surface Ni atoms. The c-C5H5 molecule is attached to the surface with its five C atoms bonding mainly with three Ni atoms. The Ni–Ni bond in the underlying surface and the C–C bonds of c-C5H5  are weakened upon adsorption. We found that the band of Ni 5dz2 orbitals plays an important role in the bonding between c-C5H5  and the surface, as do the Ni 6s and 6pz bands.