Mo_2[(p-tol)NCHN(p-tol)]_4及其阳离子电子结构和电子吸收光谱的从头算研究

Ab initio Study on the Electronic Structure of Mo_2[(p-tol)NCHN(p-tol)]_4 and Its Cation

用密度泛函理论中的 B3 LYP方法 ,采用 Lan L2 DZ基组 ,对 Mo2 (form) 4和 [Mo2 (form) 4]+ {其中(form) -=[(p-tol) NCHN(p-tol) ]-) },进行了分子轨道计算 ,明确了 Mo— Mo键具有σ2 π4 δ2 四重键的性质 .计算得到 Mo— Mo间的分子轨道顺序为π<σ<δ<σ* <δ* <π* .用单激发组态相互作用 (CIS)方法计算了 Mo2 (form) 4和 [Mo2 (form) 4]+ 的电子吸收光谱 ,Mo2 (form) 4的最低能吸收光谱λ=3 90 nm,是 1A1g→ 1Eg跃迁产生的 ,属于金属内部的电荷迁移 .[Mo2 (form) 4]+ 的最低能吸收光谱 λ=1 0 96nm,也是 1Ag→ 1Eg 跃迁产生的 。

Molecular orbital calculations by the B3LYP method have been carried out on the electronic structure of Mo 2(form) 4 and [Mo 2(form) 4] +, where (form) -=[( p tol)NCHN( p tol)] -. The nature of the quadruple metal metal bonds in the Mo—Mo was discussed in detail. Molecular orbital ordering have little difference with the result obtained by using the SCF Xα SW method. Electronic absorption spectra for Mo 2(form) 4 and [Mo 2(form) 4] + have been calculated by the single excitation configuration interactions(CIS) method and were compared with experimental result