Abstract
Tetrapyrazinoporphyrazine and its iron and cobalt derivatives have been studied by UV-visible absorption and magnetic circualr dichroism spectroscopy, electrochemistry and spectroelectrochemistry. Iron and cobalt complexes adsorbed onto a carbon electrode catalyze electroreduction of oxygen by two electrons to hydrogen peroxide over a wide range of pH values. Different from phthalocyanines, these compounds are conjectured to be protonated at nitrogens in pyrazino rings in concentrated sulfuric acid. Other results are stated in comparison with those reported for phthalocyanines.
