Electrochemical and spectroelectrochemical characterization of newly synthesized manganese, cobalt, iron and copper phthalocyanines

Abstract

Manganese, cobalt, iron, and copper phthalocyanines, tetra-substituted with 3,4-(dimethoxyphenylthio) moieties at peripheral positions, were synthesized and characterized by FT-IR, mass spectroscopy, and electronic spectroscopy. Electrochemical and spectroelectrochemical measurements exhibit that while copper phthalocyanine gives only ring-based electron transfer reactions, incorporating redox active metal centers, CoII, FeIIIAc, and MnIIIAc, into the phthalocyanine core extends the redox richness of the phthalocyanine ring with the metal-based reduction and oxidation couples of the metal centers in addition to the common phthalocyanine ring-based electron transfer processes. In situ electrocolorimetric measurements of the complexes allow quantification of color coordinates of the each electrogenerated anionic and cationic redox species. Presence of O2 in the electrolyte system influences the redox couples of the complexes due to the interaction between O2 and metallophthalocyanines having redox active metal center.