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

In the title compound, [Mn(C(5)H(9)N(2)O(7)P(2))(2)(H(2)O)(2)], the Mn(II) atom (site symmetry ) is coordinated by four phos-pho-n-ate O atoms from a pair of partially deprotonated 1-hydr-oxy-2-(imidazol-3-yl)ethane-1,1-bis-phophonic acid ligands (imhedpH(3) (-)) and two water mol-ecules, resulting in a slightly distorted trans-MnO(6) octa-hedral geometry for the metal ion. In the ligands, the imidazole units are protonated and two of the hydr-oxy O atoms of the phospho-nate groups are deprotonated and chelate the Mn(II), thus forming the neutral mol-ecule of the title compound. The two protonated O atoms within the phospho-nate groups of one imhedpH(3) (-) ligand act as hydrogen-bond acceptors for a bifurcated hydrogen bond originating from the coordinated water mol-ecule. The phospho-nate units of neigboring mol-ecules are connected with their equivalents in neighboring mol-ecules via two types of inversion-symmetric hydrogen-bonding arrangements with four and two strong O-H⋯O hydrogen bonds, respectively. The two inter-actions connect mol-ecules into infinite chains along [111] and [110], in combination forming a tightly hydrogen-bonded three-dimensional supra-molecular 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-H⋯O hydrogen bonds between the water mol-ecules and the P=O O atoms of neigboring mol-ecules.