The carotenoid astaxanthin forms novel metal ion complexes with Ca 2+, Zn 2+, and Fe 2+. MS and NMR measurements indicate that the two oxygen atoms on the terminal cyclohexene ring of astaxanthin ...

The disproportionation reaction of oxoiron(IV) porphyrin complex (II) to oxoiron(IV) porphyrin π-cation radical complex (I) and iron(III) porphyrin complex (III) have been proposed in various ...