Abstract

The title compound, [Co(C 18H 23N 10)] (BF 4) 2·H 2O, is the result of complexing a Co cation (initially in a Co II state) with tris-[2-(1H-imidazol-2- ylmethyl-eneamino)eth-yl]amine (L), obtained by a condensation process involving imidazole-2-carbaldehyde and tris-(2-amino-ethyl)amine. Both the Co cation and the ligand were modified in the synthesis process, the cation via oxidation to Co III, and the ligand via deprotonation to convert it into the 2-(2-{bis-[2-(1H-imidazol-2-ylmethyl-eneamino)eth-yl]amino}ethyl-imino-meth-yl) imidazolide anion (L -). The ligand chelates the metal centre in a hexa-dentate fashion, forming a slightly distorted octa-hedral CoN 6 chromophore. Packing is governed by N - H⋯N hydrogen bonds defining zigzag chains. A similar structure in the literature is discussed, and the wrong assignment of the oxidation state, given therein to the Co cation, is corrected. © 2008 International Union of Crystallography.