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 [Image: see text]) 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 (imhedpH(3) (−)) and two water mol­ecules, resulting in a slightly distorted trans-MnO(6) 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 imhedpH(3) (−) 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—H⋯O 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—H⋯O hydrogen bonds between the water mol­ecules and the P=O O atoms of neigboring mol­ecules.