1, 8-Naphthalene-or 1,8-anthracene-linked cofacial dizinc, dicopper, and dicobalt diphthalocyanines have been studied by solution and surface electrochemistry, spectroelectrochemistry, and electron spin resonance (ESR). These derivatives are mixtures of syn and anti isomers that have very similar electrochemistry except where we comment specifically. The phthalocyanine ring first oxidation Pc(-1)/Pt(-2), the Co(III)/Co(II), and the Co(II)/Co(I) redox couples split into two couples as a consequence of intra-ring exchange interactions. The spectra of the electrochemically oxidized or reduced species and, in particular, those of the mixed-valence species are recorded. Exciton coupling energies are derived and are seen to be related to the ground-state mixed-valence splitting energies. These are discussed in terms of structure and inter-ring distance. Cobalt derivatives immobilized onto ordinary pyrolytic graphite catalyze the electroreduction of oxygen by two electrons to hydrogen peroxide.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry