STRUCTURE AND BONDING OF ALKANETHIOLS ON CU(111) AND CU(100)

A. FERRAL; E. M. PATRITO; P. PAREDES OLIVERA

AMER CHEMICAL SOC

Año: 2006 vol. 110 p. 17050 - 17050

he local structure of the sulfur atom of methanethiolate and ethanethiolate on the Cu(111) and Cu(100) surfaces was investigated from first principles employing the periodic supercell approach in the framework of density functional theory. On the 111 surface, we investigated the √3 × √3)R30° and (2 × 2) structures, whereas on the 100 surface, we investigated the p(2 × 2) and c(2 × 2) structures. The landscape of the potential energy surface on each metal surface presents distinctive features that explain the local adsorption structure of thiolates found experimentally. On the Cu(111) surface, the energy difference between the hollow and bridge sites is only 3 kcal/mol, and consequently, adsorption sites ranging from the hollow to the bridge site were observed for increasing surface coverages. On the Cu(100) surface, there is a large energy difference of 12 kcal/mol between the hollow and bridge sites, and therefore, only the 4-fold coordination was observed. The high stabi