物理化学学报 >> 1997, Vol. 13 >> Issue (07): 603-611.doi: 10.3866/PKU.WHXB19970706

研究论文 上一篇    下一篇

锌卟啉配合物轴配反应的光谱及电子效应

阮文娟,朱志昂,陈红卫,卜显和,张智慧,邵迎,陈荣悌   

  1. 南开大学化学系,天津 300071
  • 收稿日期:1996-11-25 修回日期:1997-02-18 发布日期:1997-07-15
  • 通讯作者: 朱志昂

The Visible Spectra and Electronic Effects in Axial Coordination Reaction of Zinc Porphyrin Complexes

Ruan Wen-Juan,Zhu Zhi-Ang,Chen Hong-Wei,Bu Xian-He,Zhang Zhi-Hui,Shao Ying,Chen Rong-Ti   

  1. Department of Chemistry,Nankai Univeristy,Tianjin 300071
  • Received:1996-11-25 Revised:1997-02-18 Published:1997-07-15
  • Contact: Zhu Zhi-Ang

摘要:

用紫外-可见分光光度计研究了三种新型空间不对称金属席夫碱和四种取代咪唑与间位取代四苯基卟啉锌(ZnT(m-X)PP,X=NO2,Cl,OCH3,H,CH3)在CH2Cl2中的轴向配位反应的紫外-可见吸收光谱,发现在450-700nm间存在等吸光点;采用Rose-Drago数据处理方法确定了各体系在25℃时平衡常数,发现所研究的35个配位反应体系的配位数均为1,各配体与锌卟啉配位反应的εβ/εα及平衡常数均分别与卟啉环上取代基的Hammett参数间存在线性自由能关系.

关键词: 锌卟啉, 空间不对称金属希夫碱配合物, 紫外-可见光谱, 配位反应, 平衡常数, Hammett线性关系

Abstract:

 A thermodynamic study is reported for the coordination reaction of three new metal imidazolate complexes of unsymmetrical tetradentate schiff bases and four substituted imidazoles with zinc meta-substituted tetraphenylporphyrins (ZnT(m-X)PP, X=NO2, Cl, OCH3, H, CH3) in dichloromethane solvent by spectrophotometric technique. The isosbestic behavior is exhibited in the region between 450 nm and 700 nm. The equilibrium constants K at 25 ℃ were determined by the method of Rose-Drago. It was found that the stoichiometric number is unity for all 35 coordination reaction systems studied. A Hammett linear relationship exists between the ratio or equilibrium constant and the Hammett constant of substitutents on the phenyl ring of porphyrin.

Key words: Zinc meta-substituted tetraphenylporphyrin, Metal schiff base, UV-Vis spectra, Axial coordination reaction, Equilibrium constant, Hammett linear relationship