Salt-like hydrated complexes of formulae Na[Py8TPyzPzCo] and [Py8TPyzPzCo](SbCl6) containing CoI and CoIII, respectively, and the neutral CoII–bis(dimethyl sulfoxide) (DMSO) adduct [Py8TPyzPzCo(DMSO)2], bearing additional clathrated DMSO molecules, have been prepared and characterized {Py8TPyzPz = tetrakis[5,6-di(2-pyridyl)-2,3-pyrazino]porphyrazinato dianion}. The sodium CoI salt, the anion of which, [Py8TPyzPzCo]1–, had previously been identified by electrochemical solution studies, represents the first example of a CoI derivative of a tetrapyrrolic macrocyclic chromophore prepared as a solid pure material. Solutions of Na[Py8TPyzPzCo] in DMSO, under defined experimental conditions, allow the slow formation (months) of crystals of its corresponding CoII complex of formula [Py8TPyzPzCo(DMSO)2]·6 DMSO. The structure of the adduct, elucidated by single-crystal X-ray analysis, shows the central CoII ion surrounded by the four pyrrole N atoms of the porphyrazine macrocycle and two O atoms of the axially bonded DMSO molecules. Oxidation of the basic starting material [Py8TPyzPzCo] with phenoxathiin hexachloroantimonate (phenox-SbCl6) led to the formation of the CoIII complex [Py8TPyzPzCo](SbCl6). Full characterization of the title CoI, CoII, and CoIII species has been accomplished by solution studies and from IR, UV/Vis, EPR and X-ray crystallography data.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)