Symmetric and Unsymmetric Nickel(II) Schiff Base Complexes; Metal-Localized Versus Ligand-Localized Oxidation
Symmetric and Unsymmetric Nickel(II) Schiff Base Complexes; Metal-Localized Versus Ligand-Localized Oxidation
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DOI：
10.1080/00958972.1988.9728146
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发表时间：
1988-12
影响因子：
1.9
通讯作者：
K. A. Goldsby
中科院分区：
文献类型：
--
作者：
K. A. Goldsby
用循环伏安法研究了对称和不对称镍(II)席夫碱配合物在乙腈中的氧化行为。与镍(II)双(水杨醛)络合物在电极表面发生氧化聚合不同，本研究所考察的络合物中至少含有一种β-酮亚胺络合物，并且在电极表面被不可逆氧化。混合络合物在对称的双(水杨醛二胺)和双(β-酮亚胺)络合物之间的电位处被氧化，这意味着金属局域的氧化而不是配体的局域氧化。镍(II)席夫碱配合物的不可逆氧化反应是由镍(II)氧化成镍(III)，分子内快速电子转移生成反应性配体-自由基物种来解释的。
The oxidation of symmetric and unsymmetric nickel(II) Schiff base complexes was examined in acetonitrile by cyclic voltammetry. Unlike nickel(II) bis(salicylaldimine) complexes which undergo oxidative polymerization at the electrode surface, the complexes examined in this study contain at least one β-ketoimine chelate and are irreversibly oxidized at the electrode surface. The mixed chelate complexes are oxidized at potentials midway between those of the symmetric bis(salicylaldimine) and bis(β-ketoimine) complexes, suggesting a metal-localized rather than a ligand-localized oxidation. Oxidation of nickel(II) to nickel(III) followed by rapid intramolecular electron transfer to give reactive ligand-radical species is proposed to explain the irreversible oxidation of the nickel(II) Schiff base complexes.