Acta Crystallographica Section E (Nov 2010)
4-(Dimethylamino)pyridinium trans-diaquabis[oxalato(2−)-κ2O1,O2]chromate(III)
Abstract
In the title salt, (C7H11N2)[Cr(C2O4)2(H2O)2], the asymmetric unit contains one half-cation and one half-anion. The Cr atom, the C and N atoms involved in C— N(exocyclic) bonding and the N and H atoms of N—H groups lie on twofold rotation axis. The CrIII atom of the complex anion is six-coordinated in a distorted (4 + 2) octahedral geometry with four equatorial O atoms of two nearly coplanar oxalate and two quasi-axial aqua O atoms. In the crystal, the protonated N atoms of the pyridine rings are hydrogen bonded to the carbonyl O atoms of the anions, forming chains along [010]. These chains are connected by lateral O—H...O hydrogen bonds, stabilizing the structure.