Triaqua-1κ(3) O-μ-cyanido-1:2κ(2) N:C-penta­cyanido-2κ(5) C-tetra­kis­(dimethyl­formamide-1κO)-1-holmium(III)-2-iron(III) monohydrate

In the bimetallic cyanide-bridged title complex, [Fe(0.98)HoRu(0.02)(CN)(6)(C(3)H(7)NO)(4)(H(2)O)(3)]·H(2)O, the Ho(III) ion is in a slightly distorted square-anti­prismatic arrangement formed by seven O atoms from four dimethyl­formamide (DMF) mol­ecules and three water mol­ecules, and one N atom from a bridging cyanide group connected with the Fe(III) atom which is octa­hedrally coordinated by six cyanide groups. In the crystal, mol­ecules are held together through O—H⋯N and O—H⋯O hydrogen-bonding inter­actions to form a three-dimensional framework. Elemental analysis of one of the precursors and the crystal shows that there is a slight contamination of Fe by Ru. The Fe site displays, therefore, small substitutional disorder with site-occupancy factors Fe/Ru = 0.98:0.02. The two methyl groups of two dimethyl­formamide ligands are positionally disordered with site-occupancy factors of 0.44 (3):0.56 (3) and 0.44 (3):0.56 (3).