XPS study of metal-sulfur bonds in metal-alkanethiolate materials

X-ray photoelectron spectroscopy ( XPS) has been used to investigate the nature of the chemical bond occurring at the interface between an adsorbed alkanethiol and a metal. Both thiolate-capped colloids and metal-thiolate layered compounds have been studied. Only one sulfur species was found. and the S 2s binding energy BE) was found to depend on the nature of the metal. XPS peaks ascribed to Ag and Au core levels are not sensitive to the oxidation state of the metal.