Imidazoliumtrans-diaquadioxalatochromate(III) dihydrate

Abstract

In the title hydrated molecular salt, (C3H5N2)[Cr(C2O4)2(H2O)2]·2H2O, the complete cation is generated by a crystallographic twofold rotation axis, with one C atom lying on the rotation axis. The complete anion is generated by crystallographic inversion symmetry (CrIIIsite symmetry -1), to generate a slightly distorted CrO6octahedron withtranswater molecules and chelating oxalate dianions. The oxalate ion is almost planar (r.m.s. deviation = 0.017 Å) and the five-membered chelate ring is a shallow envelope with the metal ion displaced by 0.126 (1) Å from the ligand atoms. The crystal structure features O—H...O, N—H...O and C—H...O hydrogen bonds, which link the components into a three-dimensional network.