Benzene and carbon monoxide adsorbed on Pt(111): A LEED intensity analysis

Abstract

The structure of the Pt(III)-(2√3×4)rect-2C 6 H 6 +4CO coadsorption system has been analyzed with dynamical calculations of low-energy electron diffraction intensities. The benzene molecules are oriented with their carbon rings parallel to the surface, centered over bridge sites with local C 2v symmetry. A large carbon ring expansion is found, with possible differences in C-C bond lengths within the same ring. The carbon ring is planar within ∼0.05 Å. There are probably two carbon monoxide molecules for each benzene molecule within the unit cell. Their likely locations are also bridge sites.