(IUCr) Crystallography Journals Online

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Acta Cryst. (2009). E65, m1701-m1702 [ doi:10.1107/S160053680905065X ]

Diaquabis{[1-hydroxy-2-(1H-imidazol-3-ium-1-yl)ethane-1,1-diyl]bis(hydrogen phosphonato)}manganese(II)

Z.-C. Zhang, R.-Q. Li and Y. Zhang

Abstract: In the title compound, [Mn(C₅H₉N₂O₇P₂)₂(H₂O)₂], the Mn^II atom (site symmetry $\\overline{1}$ ) is coordinated by four phosphonate O atoms from a pair of partially deprotonated 1-hydroxy-2-(imidazol-3-yl)ethane-1,1-bisphophonic acid ligands (imhedpH₃^-) and two water molecules, resulting in a slightly distorted trans-MnO₆ octahedral geometry for the metal ion. In the ligands, the imidazole units are protonated and two of the hydroxy O atoms of the phosphonate groups are deprotonated and chelate the Mn^II, thus forming the neutral molecule of the title compound. The two protonated O atoms within the phosphonate groups of one imhedpH₃^- ligand act as hydrogen-bond acceptors for a bifurcated hydrogen bond originating from the coordinated water molecule. The phosphonate units of neigboring molecules are connected with their equivalents in neighboring molecules via two types of inversion-symmetric hydrogen-bonding arrangements with four and two strong O-HO hydrogen bonds, respectively. The two interactions connect molecules into infinite chains along [111] and [110], in combination forming a tightly hydrogen-bonded three-dimensional supramolecular network. This network is further stabilized by additional hydrogen bonds between the protonated imidazole units and one of the coordinated P-O O atoms and by additional O-HO hydrogen bonds between the water molecules and the P=O O atoms of neigboring molecules.

Online 28 November 2009