Received 14 September 2012
In the title hybrid salt, (C5H7N2)[Cr(H2O)2(C2O4)2], the CrIII ion is coordinated in a slightly distorted octahedral environment by four O atoms from two oxalate ligands in the equatorial plane and by two water O atoms in the axial sites. The 2-aminopyridinium cation is disordered over two sets of sites in a 0.800 (7):0.200 (7) ratio. In the crystal, N-HO and O-HO hydrogen bonds connect the components into a three-dimensional network. The crystal studied was an inversion twin with components in a ratio 0.75 (2):0.25 (2).
For general background to the coordination chemistry of oxalates, see: Martin et al. (2007). For the structural characterization of organic-inorganic salts containing the [Cr(H2O)2(C2O4)2]- anion, see: Bélombé et al. (2009); Nenwa et al. (2010); Chérif et al. (2011); Chérif, Abdelhak et al. (2012); Chérif, Zid et al. (2012).
Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2010); software used to prepare material for publication: WinGX Farrugia (1999).
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: LH5534 ).
The authors thank Professor Barthelemy Nyasse (Organic Chemistry Department, University of Yaounde I) for the donation of 2-aminopyridin and Tobias Storp (RWTH Aachen) for his technical support during the X-ray experiments.
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