3,4-Ethylenedioxythiophene substituted phthalocyanines

Zinc and cobalt phthalocyanines, peripherally functionalized with electroactive and electropolymerizable groups were synthesized and their electrochemical, spectroelectrochemical, and electrocolorimetric properties were studied. While cobalt phthalocyanine gives both metal-based and ring-based redox processes, zinc phthalocyanine shows only ring-based electron transfer processes. Any redox signal belonging to thiophene groups is recorded within the potential window of the electrolyte system. However, when the complexes are over-oxidized with more positive switching potential, electropolymerization of the complexes on the working electrode are recorded. Presence of the EDOT groups differentiates the colors of the electrogenerated anionic and cationic forms of the complexes which indicate possible electrochromic applications of the complexes. (C) 2011 Elsevier B.V. All rights reserved.