cis-Tetraaquabis{5-[4-(1H-imidazol-1-yl-κN 3)phenyl]tetrazolido}manganese(II) dihydrate

In the title compound, [Mn(C10H7N6)2(H2O)4]·2H2O, the complex unit comprises an Mn2+ ion, coordinated by two imidazole N atoms from cis-related monodentate 5-[4-(imidazol-1-yl)phenyl]tetrazolide ligands and four water molecules, together with two water molecules of solvation. The Mn2+ ion lies on a twofold rotation axis and has a slightly distorted octahedral geometry. The molecules are connected by O—H⋯N and O—H⋯O hydrogen bonds involving both coordinated and solvent water molecules, generating a three-dimensional structure. Two C atoms of the imidazole ring of the ligand are each disordered over two sites with occupancy factors of 0.75 and 0.25.

In the title compound, [Mn(C 10 H 7 N 6 ) 2 (H 2 O) 4 ]Á2H 2 O, the complex unit comprises an Mn 2+ ion, coordinated by two imidazole N atoms from cis-related monodentate 5-[4-(imidazol-1-yl)phenyl]tetrazolide ligands and four water molecules, together with two water molecules of solvation. The Mn 2+ ion lies on a twofold rotation axis and has a slightly distorted octahedral geometry. The molecules are connected by O-HÁ Á ÁN and O-HÁ Á ÁO hydrogen bonds involving both coordinated and solvent water molecules, generating a threedimensional structure. Two C atoms of the imidazole ring of the ligand are each disordered over two sites with occupancy factors of 0.75 and 0.25.

Related literature
For general background to the use of nitrogen-containing ligands in the construction of supramolecular coordination compounds, see: Qi et al. (2008). For the structure of the anhydrous trans-isomer of the title complex, see: Cheng (2011).
Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97. In recent years, much study has been focused on using nitrogen-containing ligands and 1,4-benzenedicarboxylic acid to construct supramolecular coordination compounds. The reason is that these supramolecular coordination assemblies exhibit not only a variety of architectures but also have potential applications as functional materials (Qi et al., 2008). In this paper, we report the synthesis and structure of the title complex [Mn(timb) imidazol-1-yl)phenyl]tetrazole}, synthesized by the hydrothermal reaction of manganese(II) acetate with Htimb in the presence of 1,4-benzenedicarboxylic acid.
In the title compound the coordination polyhedron comprises a Mn 2+ ion, two monodentate cis-related timbligands and four coordinated water molecules, together with two water molecules of solvation ( Fig. 1). The Mn 2+ lies on a twofold rotation axis and the complex has a slightly distorted octahedral geometry. Both the coordinated and solvent water molecules form intermolecular O-H···O and O-H···N hydrogen-bonding interactions (Table 1) to form a threedimensional supramolecular network. Two atoms of the imidazole ring (C2, C3) are disordered over two sites (C2A and C3A, respectively), with occupancy factors of 0.75 and 0.25. The structure of the anhydrous trans-isomer of the title complex has previously been reported (Cheng, 2011).
The product was washed with distilled water and dried, giving the yellow title compound.

Refinement
Hydrogen atoms bound to C atoms were placed in calculated positions and treated as riding on their parent atoms, with C -H = 0.93 Å and with U iso (H) = 1.2U eq (C). Water H atoms were located in a difference-Fourier analysis and both positional and isotropic displacement parameters were allowed to refine. Atom pairs C2, C2A and C3, C3A represent disordered atoms of the imidazole ring of the ligand, having site occupancies of 0.75 and 0.25.