Investigation of coordination properties of 5,10,15,20-tetra(4-OH-phenyl) porphyrin in acetonitrile and dimethylformamide

Abstract

In the present work the reactions of basic interaction of 5,10,15,20-tetra(4-OH-phenyl) porphyrin in acetonitrile with the perchloric acid are studied by the method of spectrophotometric titration. And the chemical kinetics of ligand with zinc acetate in the dimethylformamide was carried out. The constant of the basic dissociation of the protonated acids of 5,10,15,20-tetra(4-OHphenyl) porphyrin and kinetic parameters of the reaction of the formation of the zinc complex was obtained. The comparative analysis of our own obtained data and literature data according to the basic and coordination properties of 5,10,15,20-tetra(4-OH-phenyl) porphyrin and 5,10,15,20- tetrapheny porphyrin in acetonitrile and dimetilforamide in the range of 298-333K was carried out, which made it possible to draw a number of the interesting conclusions, which are concerned with the stabilization of the ionic forms of ligand in the acetonitrile and the dimethylformamide and the influence of solvent on the depth of the protonation of ligand and the kinetic rate of the formation of the corresponding zinc complexes. It is shown that the stabilization of the ionic forms of ligand upon transfer from the acetonitrile to dimethylformamide reduces the depth of the protonation of ligand, which is reflected in the decrease of the values of the dissociation constants of the cation forms of porphyrin, and the kinetic rate and the corresponding power expenditures for the reaction of the formation of ZnT(4-OH-Ph)P. It is shown that reactivity of ligand in the dipolar proton-free medium can be regulated by a change in the properties of this medium, which makes it possible to forecast the processes of the synthesis of compounds with the assigned properties.