Acta Phys. -Chim. Sin. ›› 1997, Vol. 13 ›› Issue (07): 603-611.doi: 10.3866/PKU.WHXB19970706

• ARTICLE • Previous Articles     Next Articles

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

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