团簇Mo_(3)S_(4)的成键及电子性质

Bonding and electronic properties of Mo_(3)S_(4) cluster

为研究团簇Mo_(3)S_(4)的成键作用及电子性质,以密度泛函理论为基础,在B3LYP水平上进行优化计算,得到8种稳定构型,其中单、三重态各4种。对键长、键级、电荷量以及电子自旋密度分布分析表明,各构型中成键强度由大到小为:金属-非金属键(Mo-S)>金属-金属键(Mo-Mo)>非金属-非金属键(S-S);其中Mo-S键作为稳定性的主要贡献者,具有较强的成键作用。团簇呈电中性,且电子均由Mo原子流向S原子,电子流动性的大小为:3^((1))<4^((3))<2^((3))<2^((1))<1^((3))<1^((1))<4^((1))<3^((3))。构型1(3)的电子自旋密度图的对称性与重叠程度均优于其他三重态构型,由此说明构型1^((3))的稳定性最好。

In order to study the bonding and electronic properties of cluster Mo_(3)S_(4),optimal computation at the B3LYP level was conducted based on the density functional theory,and eight stable configurations were obtained including four singlet and four triplet states.The analysis on bond length,bond order,charge quantity,and electron spin density distribution show that the order of bond strength in each configuration is:metal-nonmetal bond(Mo-S)>metal-metal bond(Mo-Mo)>nonmetal-nonmetal bond(S-S).The Mo-S bond with stronger bonding effect is the main contributor to stability.The cluster is electrically neutral,and the electrons flow from Mo atoms to S atoms.The electron mobility is 3^((1))<4^((3))<2^((3))<2^((1))<1^((3))<1^((1))<4^((1))<3^((3)).The symmetry and overlap of electron spin density map of configuration 1^((3))are better than those of the other triplet configurations,indicating that configuration 1^((3))has the best stability.