catena-Poly[[[diaquamanganese(II)]-bis[μ-1,3-bis(1H-imidazol-1-ylmethyl)benzene-κ2 N 3:N 3′]] dinitrate]

In the title compound, {[Mn(C14H14N4)2(H2O)2](NO3)2}n, the MnII ion is located on an inversion center and is coordinated by four N atoms from four 1,3-bis(1H-imidazol-1-ylmethyl)benzene (L) ligands and two water molecules in a distorted octahedral geometry. Two L ligands are related by a centre of symmetry and bridge MnII ions, forming a positively charged polymeric chain in [101]. Uncoordinated nitrate anions further link these chains into layers parallel to the ac plane via O—H⋯O hydrogen bonds.

In the title compound, {[Mn (C 14 H 14 N 4 ) 2 (H 2 O) 2 ](NO 3 ) 2 } n , the Mn II ion is located on an inversion center and is coordinated by four N atoms from four 1,3-bis(1H-imidazol-1-ylmethyl)benzene (L) ligands and two water molecules in a distorted octahedral geometry. Two L ligands are related by a centre of symmetry and bridge Mn II ions, forming a positively charged polymeric chain in [101]. Uncoordinated nitrate anions further link these chains into layers parallel to the ac plane via O-HÁ Á ÁO hydrogen bonds.

Comment
In recent years, much study has been focused on using nitrogen-containing ligands to construct the supramolecular coordination compounds. The reason is that the supramolecular coordination assemblies not only own variety of architectures but also have the potential applications as functional materials. Recently, several supramolecular complexes based on the 1,3bis(imidazol-1-yl-methyl)-benzene ligand (L) were reported (Dobrzanska et al., 2008;Dobrzanska, 2009;Yao et al., 2008).
In this paper, we report the new title compound (I) synthesized by the reaction of 1,3-bis(imidazol-1-yl-methyl)benzene and manganese dinitrate in an aqueous solution, which forms an infinite one-dimensional chain structure.
In (I) (Fig. 1), six-coordinated Mn II ion locates on an inversion center. Its environment formed by four N atoms and two O atoms has a distorted octahedral geometry. Two ligands L related by centre of symmetry bridge Mn II ions to form positively charged polymeric chain in [101] (Fig. 2). Uncoordinated nitrate anions link further these chains into layers parallel to ac plane via O-H···O hydrogen bonds (Table 1).
Suitable single crystals were grown by slow evaporation from the mixed solution. White block crystals were obtained in 63 % yield based on manganese.

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.
Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > 2sigma(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.