Crystal structure of hexakis(urea-κO)chromium(III) dichromate bromide monohydrate from synchrotron X-ray data
The title bromide salt, [Cr{CO(NH2)2}6](Cr2O7)Br·H2O, is isotypic to the corresponding chloride salt. Within the complex cation, the CrIIIatom is coordinated by six O atoms of six urea ligands, displaying a slightly distorted octahedral coordination environment. The Cr—O bond lengths involving the urea ligands are in the range 1.9534 (13)–1.9776 (12) Å. The Cr2O72−anion has a nearly staggered conformation, with a bridging angle of 130.26 (10)°. The individual components are arranged in rows extending parallel to [100]. The Br−anion links the complex cation, as well as the solvent water molecule, through N—H...Br and O—H...Br hydrogen-bonding interactions. The supramolecular architecture also includes N—H...O and O—H...O hydrogen bonding between urea N—H and water O—H donor groups and the O atoms of the Cr2O72−anion as acceptor atoms, leading to a three-dimensional network structure.