影响间位取代四苯基卟啉锌轴向配合物稳定因素的研究

用光度滴定法研究了间位取代四苯基卟啉锌ZnT(m-X)PP,X=NO₂,Cl,OCH₃,H,CH₃]与3种新型空间不对称金属席夫碱和4种取代咪唑的轴向配位反应动力学.采用Rose-Drago数据处理方法确定了各反应体系的平衡常数,探讨了温度、轴向配体、卟啉环上的取代基对轴向配合物稳定性的影响,发现在5种间位取代四苯基卟啉锌与7种轴向配体的配位反应中均存在线性自由能关系和等平衡关系,对所研究体系采用不同的方法求取等平衡温度β及温度T→∞时的反应对电子效应的敏感系数ρ_∞,得到吻合的结果.

A Study of the Effect on the Stability of Axial Complex of meso-Tetra(m-substituted)phenylporphyrin Zinc

A thermodynamic study is reported for the coordination reaction of meso-tetra(m-substituted)phenylporphyrin zinc ZnT(m-X)PP, X=NO₂, Cl, OCH₃, H, CH₃] with four substituted imidazoles and three new metal imidazolate complexs of unsymmetrical tetradentate Schiff bases in CH₂Cl₂ solvent by spectrophotometer technique. The equilibrium constant K was determined by Rose Drago's method. The effect of temperature, axial ligands, the substitutents of porphyrin on the stability of complex were studied. It was found that Hammett linear and isoequilibrium relationships exist in the system. The values β and ρ_∞ obtained by different approaches in the system are in agreement with each other.