Soft X-ray photo-electron spectroscopy of the S 2p levels at relatively high spectral resolution was used to characterize the interaction of methanethiol, CH3SH, ethanethiol, C2H5SH and dimethyl disulphide, (CH3S)2 with a Cu(111) surface at temperatures from approximately 130 to 500K. The results were consistent with previous reports of the formation of a surface thiolate species at intermediate temperatures, but also provide clear evidence for two distinct surface intermediates in addition to the intact molecules and chemisorbed atomic sulphur reported previously for this surface. These two intermediates appear to be similar to the two thiolate species reported in studies on Ni(111). Prior structural studies of the Cu(111)/CH3S- surface at room temperature show the surface to be reconstructed, and the lower temperature species identified here was assigned to a thiolate species on an unreconstructed surface, reconstruction being hindered at low temperatures. Additional evidence was found for two different atomic sulphur states in a narrow temperature range.

Characterization of Thiolate Species Formation on Cu(111) using Soft X-Ray Photoelectron Spectroscopy. M.S.Kariapper, G.F.Grom, G.J.Jackson, C.F.McConville, D.P.Woodruff: Journal of Physics - Condensed Matter, 1998, 10[39], 8661-70