The Effect of a Solvent on Complexation of Zn Porphyrinates with Pyridine

摘要

Spectrophotometric titration was used to study complexation reactions of Zn 2,3,7,8,12,13,17,18-octaethylporphyrinate and Zn 5,10,15,20-tetraphenylporphyrinate with pyridine in binary solvents toluene-methanol and toluene-ethanol at different alcohol concentrations at 20 deg C.Capability of both porphyrinates to give complexes with pyridine in a binary solvent,i.e.,toluene-monobasic alcohol,was found to decrease by more than one order of magnitude as the alcohol concentration increased from 0 to 1 mole fraction.The effect of the solvent polarity and extent of its association due to hydrogen bonds on the complexing capability of both porphyrinates was discussed.