双核浆叶式钨配合物电子结构和电子光谱的理论研究

Ab initio study on the electronic structure of ditungsten (Ⅱ) compound

用密度函数理论中的B3LYP方法 ,对甲脒做配体的过渡金属双核浆叶式配合物W2 (form) 4((form) -=[(p -tol)NCHN(p -tol) ]-)进行了分子轨道计算 .结果表明 ,W—W键具有σ2 π4 δ2 四重键的性质 ,W—W间的成键和反键分子轨道顺序为σ<π <δ <σ <π <δ .用单激发组态相互作用 (CIS)方法计算了W2 (form) 4的电子吸收光谱 ,得到这种配合物的最低能吸收光谱为λ=496nm ,这是δ(dxy)→σ (spz)跃迁产生的 。

The B3LYP calculations were carried out to investigate the electronic structures of W 2(form) 4((form) -=[(p-tol)NCHN(p-tol)] -). The nature of the quadruple metal-metal bonds σ 2π 4δ 2 in the W-W was discussed detailedly. The ordering of the bonding and antibonding molecular orbitals between the metals are σ<π<δ<σ *<π *<δ * .Electronic absorption spectrums for W 2(form) 4 were calculated by the single excitation configuration interactions (CIS) method. The lowest calculated transition of W 2(form) 4 are δ[d xy ) (W)- d xy (W)]→ σ [sp z (W)- sp z (W)] at 496 nm compared with, then experimental values 443 nm.