Diaquabis(4-carboxy-2-propyl-1H-imidazole-5-carboxylato-κ2 N 3,O 4)cobalt(II) N,N-dimethylformamide disolvate

In the title complex, [Co(C8H9N2O4)2(H2O)2]·2C3H7NO, the CoII cation (site symmetry ) is six-coordinated by two 5-carboxy-2-propyl-1H-imidazole-4-carboxylate ligands and two water molecules in a distorted octahedral environment. In the crystal structure, the complex molecules and dimethylformamide solvent molecules are linked by extensive O—H⋯O and N—H⋯O hydrogen bonding into sheets lying parallel to (21).

In the title complex, [Co(C 8 H 9 N 2 O 4 ) 2 (H 2 O) 2 ]Á2C 3 H 7 NO, the Co II cation (site symmetry 1) is six-coordinated by two 5carboxy-2-propyl-1H-imidazole-4-carboxylate ligands and two water molecules in a distorted octahedral environment. In the crystal structure, the complex molecules and dimethylformamide solvent molecules are linked by extensive O-HÁ Á ÁO and N-HÁ Á ÁO hydrogen bonding into sheets lying parallel to (211).
As illustrated in figure 1, the title complex molecule is isomorphous with Ni(II), Mn(II) and Cu(II) analogs (Li et al., 2010a,b,c,d;Yan et al., 2010;He et al., 2010), Similar structural description applies to the present isomorphous complex.the Co II cation lying on the inversion center, is six-coordinated CoN 2 O 4 in a slightly distorted octahedral geometry, constructed by the two pairs of N and O atoms from H 2 pimda in the equatorial plane, and two coordinate water O atoms occipying the axial position. The Co-O bond lengths and Co-N bond lengths, all of which are within the range of those observed for other Co complexes based on the similar ligand (Lu et al., 2008;Wang et al., 2004). Each H 3 pimda adopts bidentate coordination mode to chelate Co II atom through imidazole N atom and O atom from the protonated carboxyl group, the complex molecules and dimethylformamide solvent molecules are linked by extensive O-H···O and N-H···O hydrogen bonds into a two-dimensional supramolecular network parallel to (001).

Experimental
A mixture of Co(NO3) 2 (0.5 mmol, 0.06 g) and 2-propyl-1H-imidazole-4,5-dicarboxylic acid(0.5 mmol, 0.99 g) in 15 ml of DMF solution was sealed in an autoclave equipped with a Teflon liner (20 ml) and then heated at 413k for 3 days. Crystals of the title compound were obtained by slow evaporation of the solvent at room temperature.
supplementary materials sup-2 Refinement Water H atoms were located in a difference Fourier map and were allowed to ride on the parent atom, with U iso (H) = 1.5U eq (O). Carboxyl H atoms were located in a difference map and refined with distance restraints, U iso (H) = 1.5U eq (O).
Other H atoms were placed at calculated positions and were treated as riding on parent atoms with C-H = 0.96 (methyl), 0.97 (methylene) and N-H = 0.86 Å, U iso (H) = 1.2 or 1.5U eq (C,N). Crystal data [Co(C 8