[M(SS)(NN)](M=Zn2+,Cd2+)配合物分子内跃迁与结构的关系

报道了配合物[M(SS)(NN)](M=Zn2 ,Cd2 )(SS=mnt2-,1,2-二氰基乙烯-1,2-二硫醇离子,NN=5-NO2-phen,5-硝基-1,10-邻菲咯啉)的合成,探讨了Zn(SS)(NN)和Cd(SS)(NN)在二甲基亚砜(DM-SO)、二甲基甲酰胺(DMF)、丙酮(acetone)、吡啶(Py)等溶剂中的电子吸收光谱。研究发现配合物的紫外区的吸收带270～280nm,320～350nm,350～390nm本质上属于配体mnt2-,5-NO2-phen内部的πb→π*跃迁,可见光区400～500nm本质上属于配体mnt2-到配体5-NO2-phen的荷移跃迁(LL′CT)。确认了标题配合物的荷移跃迁光谱在相关分子轨道能级图中的对应关系。标题配合物的LL′CT吸收带与组成相似配合物M(SS)(NN)(M=Co2 ,Fe2 ,Ni2 ,Cu2 )的对应吸收带相比较弱一些,这是由于[M(SS)(NN)](M=Zn2 ,Cd2 )的LL′CT谱带(7b2→7b1)是部分解除轨道禁阻的跃迁。

Relation between Complexes Iotramolecular Transfer and Structure of [M(SS)(NN)](M=Zn2+, Cd2+)

The title complexes of [M(SS)(NN)](M = Zn2+, Cd+; SS = 1,2-dicyano 1,2-ethylene -dithiolate or maleonitriledithiolate; NN = 5-nitro-1,10 phenanthroline) were synthesized. The electronic absorption spectra of complexes [M(SS)(NN)] in DMSO, DMF, acetone and Py were reported. The spectra absorption bands 270-280 nm, 320-350 nm and 350-390 nm are the intraligand pi(b) --> pi* transfer of ligand mnt(2-) and 5-NOz-phen. The spectra absorption band 400-500 nm is intramolecular charge transfer (LL'CT) from a ligand (mnt(2-)) to another ligand (5-NO2- phen) The relation between electronic spectra absorption band and correlative transition in the molecular orbital energy level diagram of the complexes was investigated. The LL'CT band of the title complexes is weaker by comparison with M(SS) (NN) (M = Co2+, Fe2+, Ni2+ and Cu2+). The LL'CT band of [M(SS) (NN)](M = Zn2+, Cd2+) (7b2 to 7b1) is symmetry forbidden.