title: Crystal structure of tris-[4-(di-methyl-amino)-pyridinium] tris-(oxalato-κ(2) O,O')chromate(III) tetra-hydrate.
abstract: In the title hybrid salt, (C7H11N2)3[Cr(C2O4)3]·4H2O, the central Cr(III) ion of the complex anion (point group symmetry 2) is coordinated by six O atoms from three chelating oxalate(2-) ligands in a slightly distorted octa-hedral coordination sphere. The Cr-O bond lengths vary from 1.9577 (11) to 1.9804 (11) Å, while the chelate O-Cr-O angles range from 82.11 (6) to 93.41 (5)°. The 4-(di-methyl-amino)-pyridinium cations (one situated in a general position and one on a twofold rotation axis) are protonated at the pyridine N atoms. In the crystal, N-H⋯O and O-H⋯O hydrogen bonds link the cations and anions into a three-dimensional network. π-π inter-actions between the pyridine rings of adjacent cations provide additional stabilization of the crystal packing, with the closest centroid-to-centroid distances being 3.541 (1) and 3.575 (1) Å.
authors.affiliation: Department of Inorganic Chemistry, University of Yaounde 1, POB 812 Yaounde, Cameroon.
authors.forename: Noé
authors.initials: N
authors.lastname: Makon Ma Houga
authors.affiliation: Unité de Catalyse et de Chimie du Solide, UMR 8181, Ecole Nationale Supérieure de Chimie de Lille, Université Lille1, 59650 Villeneuve d'Ascq Cedex, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Capet
authors.affiliation: Department of Inorganic Chemistry, University of Yaounde 1, POB 812 Yaounde, Cameroon.
authors.forename: Justin
authors.initials: J
authors.lastname: Nenwa
authors.affiliation: Higher Teacher Training College, Chemistry Department, University of Yaounde 1, POB 47, Yaounde, Cameroon.
authors.forename: Gouet
authors.initials: G
authors.lastname: Bebga
authors.affiliation: UFR de Physique, Université Lille1, 59650 Villeneuve d'Ascq Cedex, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Foulon
keywords: 4-(di­methyl­amino)­pyridine; crystal structure; hybrid salt; hydrogen bonding; tris­(oxalato)chromate(III); π–π inter­actions