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采用密度泛函理论方法研究了具有仿生固氮结构的两类化合物[Cp*Fe(μ-η~2:η~2-bdt)(μ-η~1:η~1-Me N=NMe)Fe Cp*]以及[Cp*Fe(μ-SEt)_2(μ-η~1:η~1-Me N=NMe)Fe Cp*]的90种不同结构,调变过渡金属中心,研究不同自旋态下(单重态和三重态)具有side-on或end-on配位键型的双核双氮过渡金属配合物,基于计算结果分析了BDT(邻苯二硫酚)和乙基类型配体的不同过渡金属配合物活化双氮的程度.研究结果表明,N—N键活化程度与配合物过渡金属中心所在周期存在密切关系,更高周期对双氮的活化程度更高,同周期金属过渡金属配合物对N—N键的活化程度从第四副族至第八族呈现折线型下降,同时,过渡金属中心的外层价电子数的奇偶性对双氮的活化程度具有一定影响.此外,side-on键型对双氮的活化程度要高于end-on键型,具有不同基团的同种骨架配体对N—N键的活化能力没有明显区别.
Two kinds of compounds [Cp * Fe (μ-η ~ 2: η ~ 2-bdt) (μ-η ~ 1: η ~ 1-Me N = NMe) Fe have been studied by using density functional theory 90 different structures of [Cp * Fe (μ-SEt) _2 (μ-η ~ 1: η ~ 1-Me N = NMe) Fe Cp *] State (singlet and triplet) binuclear dinitrogen transition metal complexes with side-on or end-on coordination type bonds. Based on the calculated results, BDT (orthophthalic dithiol) and ethyl type ligands Of the different transition metal complexes activation of the degree of nitrogen.The results show that the degree of activation of N-N bond with the complex transition metal centers are closely related to the period, the higher cycle of the activation of a higher degree of nitrogen, the same period of metal transition The degree of activation of the N-N bond by the metal complex shows a polygonal decline from the fourth subgroup to the eighth subgroup, and the parity of the outer valence electron number of the transition metal center has an influence on the activation degree of the dinitrogen. , the side-on type is more active on the bis-nitrogen than the end-on type, and the same type of ligand with different groups has no obvious difference in the activation ability of N-N bond.