Osmium carbonyl clusters: XPS characterization of some catalyst precursors

Abstract

An XPS study on selected Os cluster compounds is reported. Investigated compounds include: Os 3(CO) 12, Os 6(CO) 13, H 2Os 3(CO) 10, HOs 3(CO 11)(OC 6H 5), [(C 3H 5) 3P) 2N] + [HOs 3(CO) 11] − and the Os(II) species Os(CO) 3Cl 2 and Os(CO) 2Cl 2. Os 4 f binding energies (b.e.) are discussed in terms of a quantitative empirical model already proposed by Feltham and Brant, to describe observed b.e. shifts for substituted Os carbonyls in terms of parameter values to be assigned to the ligands. New parameter values, which, in some cases, differ considerably from previously reported ones, are proposed to account for the observed b.e. shifts. The larger role played by constitutive besides additive effects on the experimental b.e. trends is also discussed with reference to the particular electronic structures represented by molecular cluster compounds.