A bonding study of c-C5H8 adsorption on Pt(111)

S. SIMONETTI; P. JASEN; E. GONZALEZ; G. BRIZUELA; A. JUAN

Applied Surface Science

Año: 2006 vol. 252 p. 7515 - 7522

The chemisorption of cyclopentane (c-C5H8) on Pt(111) has been studied using a qualitative band-structure calculations in the framework of tight-binding implementation with the YAeHMOP package. We modeled the metal surface by a two dimensional slab of finite thickness with an over layer of c-C5H8, in a (3 x 3) di-sigma geometry. The c-C5H8 molecule is attached to the surface with its C=C atoms bonded mainly with two Pt atoms while the opposite CH2 bends towards the surface. The Pt-Pt bonds in the underlying surface and the C-C bonds of c-C5H8 are weakened upon the chemisorption. A noticeable Pt-H and Pt-C interactions has been observed. We found that of Pt 5dz2 band plays an important role in the bonding between c-C5H8  and the surface, as do the Pt 6s and 6pz bands. The HOMO-LUMO bands of c-C5H8 are very dispersed, indicative of a strong interaction with the metal surface.