分类: 化学 >> 物理化学 提交时间: 2017-11-05 合作期刊: 《结构化学》
摘要: Density functional theory (DFT) and coupled cluster theory (CCSD(T)) calculations were employed to investigate the geometric and electronic structures of a range of dinuclear molybdenum sulfide clusters, Mo2Sn– and Mo2Sn (n = 4~8). The results showed that the sulfur atoms tended to occupy the terminal sites of the clusters continuously in the process of sequential sulfidation. After the oxidation state of Mo atoms reached the maximum of +6, diverse disulfur ligands emerged in the sulfur-rich Mo2Sn–/0 (n = 7, 8) clusters. The driving forces of removing a sulfur atom from different S ligands in Mo2Sn–/0 (n = 4~8) clusters, especially from those disulfur units, were evaluated. The corresponding order may provide insight into the pretreatment of fresh MoS2 catalysts. Vertical detachment energies (VDEs) were predicted according to the Generalized Koopmans’ theorem, and then the photoelectron spectra (PES) were simulated. Molecular orbital and spin density values were analyzed to elucidate the chemical bonding and the evolutionary behavior in the dinuclear molybdenum sulfide clusters.