c-C5H5- on a Ni(111) Surface: Theoretical Study of the Adsorption, Electronic Structure and Bonding

E. GERMAN; S. SIMONETTI; E. PRONSATO; A. JUAN; G. BRIZUELA

APPLIED SURFACE SCIENCE

ELSEVIER SCIENCE BV

Año: 2008 vol. 254 p. 5831 - 5836

0169-4332

In the present work, ASED-MO method is applied to study the adsorption of cyclopendienile anion on a Ni(111) surface [1]. 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, but the H atoms are tilted away 17° from the metal surface. We modeled 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.