Complexation of the highly branched, pentadecadentate chelating ligand cis,cis-1,3,5-cyclohexanetriamine-N,N,N',N',N",N"-hexaacetic acid (H(6)L) with iron(III) and sodium cations in the presence of carbonate anions leads to the formation of an [Fe6L2] cluster comprising an [Fe6] cage linked by 12 exo-coordinated sodium cations to form an extended 3D array.