metal-organic compounds
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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 (CrIII site symmetry -1), to generate a slightly distorted CrO6 octahedron with trans water 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—HO, N—HO and C—HO hydrogen bonds, which link the components into a three-dimensional network.