Electrochemical synthesis of catalytically active linear and cross-linked polyporphyrins

Abstract

In this work, the electrochemical method was applied to prepare linear and 3D polyporphyrins based on 5,15-di(4-aminophenyl)− 10,20-diphenylporphyrin and 5,10,15-tri(4-aminophenyl)− 20-phenylporphyrin. The formation of polyporphyrins consisted in electrooxidation of porphyrins via the amino-groups of amino-phenyl substituents. Based on the assumed structure of the polyporpyrins, UV–vis spectroscopy data, structure of the porphyrin monomers and comparison of the swelling degrees, it was established that poly-5,15-di(4-aminophenyl)− 10,20-diphenylporphyrin has a linear structure, whereas poly-5,10,15-tri(4-aminophenyl)− 20-phenylporphyrin is a cross-linked polymer. The branched cross-linked polyporphyrin obtained from 5,10,15-tri(4-aminophenyl)− 20-phenylporphyrin on conductive substrates is much more effective in accelerating the electrons, which improves the catalytic characteristics of the oxygen electroreduction catalyst.