Triclinic Form of Tetraaqua(orotato-N,O)magnesium(II) Hydrate at 153K

In the title complex, Mg(C₅H₂N₂O₄)(H₂O)₄].H₂O, orotic acid (uracil-6-carboxylic acid or 1,2,3,6-tetrahydro-2,6-dioxo-4-pyrimidinecarboxylic acid) coordinates to Mg through the deprotonated heterocyclic N1 atom and the O atom of the adjacent carboxylate group. The coordination sphere of the Mg atom is octahedral with water molecules occupying the four remaining coordination positions. The bond lengths in the coordination sphere are in the range 2.0128 (13) to 2.1295 (13) Å for the Mg-O bonds and 2.1663 (14) Å for the Mg-N bond. The C=O bond lengths for the exocyclic O2 and O4 atoms of the orotato ligand are 1.247 (2) and 1.249 (2) Å, respectively.

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