화학공학소재연구정보센터
Applied Surface Science, Vol.254, No.18, 5831-5836, 2008
c-C5H5 on a Ni(111) surface: Theoretical study of the adsorption, electronic structure and bonding
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. at, 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 5d(z2) orbitals plays an important role in the bonding between c-C5H5 and the surface, as do the Ni 6s and 6p(z) bands. (C) 2008 Elsevier B.V. All rights reserved.