席夫碱配合物的研究(Ⅲ)——Fe(Ⅲ)配合物的循环伏安特性

Studies on Schiff Base Complexes Fe(Ⅲ)——Cyclic Voltammetric Behavior of Fe(Ⅲ)Complexes

用循环伏安法研究 Schiff 碱铁(Ⅲ)配合物的氧化—还原特性。结果表明,铁配合物的自旋态与反铁磁性相互作用对 Fe^(3+)的还原影响十分显著。对于 Fe(Ⅲ)—O—Fe(Ⅲ)体系,还原时因有电子进入反键轨道,故伴随 Fe—O 键的离解,显示出明显的不可逆还原特征。

Cyclic voltammetry has been performed on the Fe(Ⅲ) com- plexes with Schiff bases in DMF.On the basis of the experimental results the electro—chemical properties of the compounds are discussed in terms of coor- dination chemistry.The low—spin complexes give relatively nagative E_(p.c) Val- ues as a result of the coordination effect.The μ—oxo dimers show a irre- versible process,since electro—chemical reduction transfers electrons into the highest energy e_u~* orbital with net antibonding character and this explains the greater extent of dissociation on going from the Fe(ΔⅢ)—O—Fe(Ⅲ) to the Fe (Ⅲ)—O—Fe (Ⅲ) dimer,and the complete lack of stablity of the Fe (Ⅱ)—O—Fe(Ⅱ) dimer.