Investigation of electronic structure of {Nb2S4}4+ clusters by XES, XPS and DFT calculations

Abstract For the following compounds [Nb 2 S 4 (acac) 4 ] (acac = acetylacetonate), К 4 [Nb 2 S 4 (ox) 4 ] (ox = oxalate) and Nb 2 S 4 Br 4 containing dinuclear cluster core {(Nb 4+ ) 2 (μ-S 2 2− ) 2 } 4+ (simply {Nb 2 S 4 } 4+ ) the electronic structure has been experimentally and theoretically investigated through X-ray emission (XES), X-ray photoelectron (XPS) spectroscopies and Density functional theory (DFT). The bonding and antibonding highest occupied molecular orbitals (HOMOs) observed in the X-ray emission spectra have been characterized by the analysis of overlap populations and the partial atomic composition considering the nature of the electron density distribution. Furthermore, the effective atomic charges have been determined.