Crystal structure of bis­[bis­(1,4,7-tri­aza­cyclo­nonane-κ(3) N,N′,N′′)chromium(III)] tris­(tetra­chlorido­zincate) monohydrate from synchrotron X-ray data

The structure of the title compound, [Cr(tacn)(2)](2)[ZnCl(4)](3)·H(2)O (tacn is 1,4,7-tri­aza­cyclo­nonane; C(6)H(15)N(3)), has been determined from synchrotron X-ray data. Each Cr(III) cation is coordinated by the six N atoms from the two tacn ligands, displaying a distorted octa­hedral geometry. Three distorted tetra­hedral [ZnCl(4)](2−) anions and one lattice water mol­ecule lie outside this coordination sphere. The Cr—N bond lengths are in the range 2.0621 (11) to 2.0851 (12) Å, while the mean inner N—Cr—N bond angle is 82.51 (5)°. The crystal packing is stabilized by hydrogen-bonding inter­actions with the N—H groups of the tacn ligands and the water O—H groups acting as donors, and the O atoms of the water mol­ecules and Cl atoms of the [ZnCl(4)](2−) anions as acceptors. Overall these contacts lead to the formation of a three-dimensional network.