The molecule is a cyclic tetrapyrrole anion obtained by deprotonation of the carboxy groups of cobalt-sirohydrochlorin; major species at pH 7.3. It is a conjugate base of a cobalt-sirohydrochlorin.
cobalt;3-[(2S,3S,7S,8S)-7,13,17-tris(2-carboxylatoethyl)-3,8,12,18-tetrakis(carboxylatomethyl)-3,8-dimethyl-2,7-dihydroporphyrin-21,23-diid-2-yl]propanoate