Studies on the Electronic Structure and Assembly Mechanism of Co₆S₈（PEt₃）₆ⁿ Clusters

The studies on the electronic structrure and assembly mechanism ofCo₆S₈(PH₃)₆ⁿ, the cluster models ofCo₆S₈(PEt₃)₆ⁿ (n=-1, 0, + 1, +2), have been carried out by using Gaussian 94w package and taking LanL2DZ basis set. The stabilities of the clusters, the roles played on the formation of clusters by S and P atoms, and the assembly mechanism from combination of Co₃ (μ₂-S)₃ (μ₃- S) (PH₃)₃ⁿ, (n=+ 1, 0) have been investigated. The calctilation results show thatCo₆S₈(PEt₃)₆^- is not stable, WhereasCo₆S₈(PEt₃)₆ⁿ (n=0, + 1, +2) are relatively stable. The S atoms play more important roles on the formation of clusters than the P atoms.The results are agreeing with the experiments satisfactorily. Meanwhile, the theoretical analyses for the assembly mechanism are carried out too from energetics and overlapping of the orbitals.