Nickel(II) complexes with Schiff-bases obtained by condensation of 1,3-propanediamine with salicylaldehyde and thiosalicylaldehyde, which present a N2OS or N2S2 co-ordination sphere, were synthesized and studied. The molecular and crystal structure of the asymmetric complex [2-(3-[(3,5-dichloro-2-hydroxyphenyl)methyleneamino]propyl}iminomethylene)benzenethiolato-O,N,N′,S]nickel(II) [Ni(t-salCl2salpd)] has been determined by X-ray crystallography and shows a tetrahedrally distorted square-planar co-ordination geometry for the nickel center. The complexes were characterized by spectroscopic and electrochemical techniques and the results were used to assess the influence of the donor-atoms on their chemical properties. The results obtained show that the compounds may be reduced, either chemically or electrochemically, to Ni(I) complexes. Reduction potentials were found to be strongly dependent on the tetrahedral distortion of the Ni(II) complexes. EPR parameters for Ni(I) complexes, although not very sensitive to ligand substituents, show a regular dependence on the co-ordination set and the tetrahedral distortion of the complexes.
研究人员合成并研究了由
1,3-丙二胺与
水杨醛和
硫代
水杨醛缩合得到的具有 N2OS 或 N2S2 配位层的希夫碱
镍(II)配合物。通过 X 射线晶体学确定了不对称配合物 [2-(3-[(3,5-二
氯-2-羟基苯基)亚甲基
氨基]丙基}亚
氨基亚甲基)
苯硫酚-O,N,N′,S]
镍(II)[Ni(t-salCl2salpd)] 的分子和晶体结构,并显示出
镍中心的四面体畸变方平面配位几何。通过光谱和电
化学技术对这些复合物进行了表征,并利用表征结果评估了供体原子对其
化学性质的影响。研究结果表明,这些化合物可以通过
化学或电
化学方法还原成 Ni(I) 复合物。还原电位与 Ni(II) 复合物的四面体畸变密切相关。
镍(I)络合物的 EPR 参数虽然对
配体取代基不太敏感,但却显示出对配位集和络合物四面体畸变的规律性依赖。