团簇NiCo_(2)S_(4)极性及成键性质

Polarity and Bonding Properties of Cluster NiCo_(2)S_(4)

依据密度泛函理论(DFT)在B3LYP/Lan12dz水平下对团簇NiCo_(2)S_(4)进行优化计算,确定11种优化构型,分析其极性和成键性质,结果表明:构型1^((3))极性最大,构型4^((3))极性最小。键长分析中,Ni-Co和Co-Co键存在拮抗作用,Ni-S、Co-S和S-S键存在协同作用,同种金属原子成键效果最佳,同种非金属原子最差。键级分析中,构型4^((1))和构型6^((1))的各键键级全为正值,成键强度强。态密度图分析得到主要存在的化学键杂化方式:三重态构型中,NI-Co键和Co-Co键存在d-d杂化、p-p杂化,NI-S键和Co-S键存在p-d杂化,S-S键存在p-p杂化;单重态构型中,NI-Co键、NI-S键、Co-S键、Co-Co键和S-S键存在d-d杂化,且NI-Co键和Co-Co键还存在p-p杂化。

Based on density functional theory(DFT), the cluster NiCo_(2)S_(4) was optimized at B3LYP/Lan12dz level in order to determin eleven optimized configurations and analyze their polarity and bonding properties. The results showed that the polarity of configuration 1^((3)) is the largest and the polarity of configuration 4^((3)) is the smallest. In the bond length analysis, Ni-Co and Co-Co bonds have antagonistic effect, and Ni-S, Co-S and S-S bonds have synergistic effect. The bonding effect of the same metal atom is the best, and the same non-metallic atom is the worst. In the bond level analysis, the bond levels of configuration 4^((1)) and configuration 6^((1)) are all positive, and the bonding strength is strong. The main chemical bond hybridization modes are obtained by density of states diagram analysis: in the triplet configurations, there are d-d and p-p hybridization in Ni-Co bond and Co-Co bond, p-d hybridization in Ni-S bond and Co-S bond, and p-p hybridization in S-S bond;in the singlet configurations, there is d-d hybridization in Ni-Co bond, Ni-S bond, Co-S bond, Co-Co bond and S-S bond, and p-p hybridization in Ni-Co bond.