Experimental

R factor = 0.061; wR factor = 0.160; data-to-parameter ratio = 18.0. The title compound, (C5H6N)[Cr(C2O4)2(H2O)2], contains one protonated pyridine molecule and one [Cr(C2O4)2-(H2O)2] complex anion in the asymmetric unit. The CrIII in the complex anion is coordinated in a distorted octahedral environment by two O atoms from two cis water molecules and four O atoms from two chelating oxalate dianions. The crystal packing is stabilized by intermolecular N— H O(oxalate) and O—H O(oxalate) hydrogen bonds and by – stacking interactions (centroid–centroid distance = 3.602 Å) between pyridine rings, thereby building up a three-dimensional network. Related literature For the structural characterization of organic–inorganic salts containing the [Cr(C2O4)2(H2O)2] anion, see: Bélombe ́ et al. (2009); Nenwa et al. (2010, 2012); Chérif et al. (2011); Chérif