Crystal structure of tris(trans-1,2-cyclohexanediamine-κ2N,N′)chromium(III) tetrachloridozincate chloride trihydrate from synchrotron data

Abstract

The structure of the title double salt, [Cr(rac-chxn)3][ZnCl4]Cl·3H2O (chxn istrans-1,2-cyclohexanediamine; C6H14N2), has been determined from synchrotron data. The CrIIIion is coordinated by six N atoms of three chelating chxn ligands, displaying a slightly distorted octahedral coordination environment. The distorted tetrahedral [ZnCl4]2−anion, the isolated Cl−anion and three lattice water molecules remain outside the coordination sphere. The Cr—N(chxn) bond lengths are in a narrow range between 2.0737 (12) and 2.0928 (12) Å; the mean N—Cr—N bite angle is 82.1 (4)°. The crystal packing is stabilized by hydrogen-bonding interactions between the amino groups of the chxn ligands and the water molecules as donor groups, and O atoms of the water molecules, chloride anions and Cl atoms of the [ZnCl4]2−anions as acceptor groups, leading to the formation of a three-dimensional network. The [ZnCl4]2−anion is disordered over two sets of sites with an occupancy ratio of 0.94:0.06.