氮杂大环双核铜锌金属配合物的合成结构及溶液中配位稳定性研究

在合成模型化合物之前 ,有必要先了解合成的大环配体在溶液中与金属离子的配位行为及其稳定性 ,以便选择不同结构的大环配体和控制反应的 p H值合成出结构和催化性能较好的模型化合物 [1～ 3] .本文报道了大环配体与 Cu( )和 Zn( )形成的配合物 ,对其结构和溶液中的配位稳定性进行了研究 .1　实验部分1 .1　试剂与仪器配体 L以 2 ,6-吡啶二甲醛和二乙烯三胺为原料 ,按文献 [4]报道的方法经 2 + 2合成得到 .其纯度经元素分析、红外光谱、核磁共振氢谱和质谱鉴定 .其它试剂均为分析纯 . p H滴定采用二次蒸馏水 .Perkin- Elmer 2 4 0型元…

Synthesis, Structure and Stability of Binuclear Metal Complexes with Macrocyclic Ligand

The macrocyclic ligand(L) and its dinuclear copper(Ⅱ) and zinc(Ⅱ) complexes have been synthesized. The crystal structure of [Cu 2L(Him)₂](ClO₄)₄·2H₂O has been determined by single crystal X-ray diffraction. It crystallizes in a monoclinic system, the space group P₂ 1/c, a=0.9512(2) nm, b=2.0104(4) nm, c=1.2025(2) nm, β-=98.89(3)°, V=2.2719(8) nm³, Z=2, D_c=1.599 Mg/m³, F(000) = 876, R=0.0591, wR=0.1733, GOF(F)=1.009. The copper(Ⅱ) atom is five coordinated with four nitrogen atoms of the macrocyclic ligand and one nitrogen atom of imidazole. The stepwise stability constants of the 1∶1 and 2∶1 molar ratios of Cu to Land Zn to Lcomplexes were determined by potentiometric titration in KCl supporting electrolyte(0.100 mol/L) at 25 ℃. The results indicated that zinc(Ⅱ) ion can form hydroxide bridged dinuclear complex [Zn₂(OH)L]³⁺, while the copper(Ⅱ) ion can only form dinuclear complex [Cu₂L]³⁺ with macrocyclic ligand.