Transition metal sulfide clusters below the cluster–platelet transition: Theory and experiment

Abstract

Abstract The structural and electronic properties of neutral and anionic molybdenum sulfide clusters with the composition Mo 3 S n ( n = 0–12) were studied by density‐functional calculations. The theoretical results are confirmed by a comparison with photoelectron spectra of the corresponding W 3 S anions providing experimental values for the vertical detachment energies (VDEs) and the highest occupied (HOMO) and lowest unoccupied (LUMO) gaps. For sulfur contents up to n = 9 the clusters are composed of a central Mo 3 unit, which is decorated by bridging, terminal, and three‐fold coordinated S atoms. For n > 9, a cleavage of the Mo 3 center is observed. The formation of disulfide like ions is found for Mo 3 S 9 and larger species. In accordance with investigations of MoS n , Mo 2 S n , and Mo 4 S n clusters, the heat of formation and the VDE reaches a maximum in the sulfur‐rich region beyond the composition Mo:S = 1:2.