Crystal structure of tetra-kis-(imidazolium) hexa-kis-(imidazole-κN)cobalt(II) bis-(benzene-1,3,5-tri-carboxyl-ate) dihydrate.

The title compound, (C3H5N2)4[Co(C3H4N2)6](C9H3O6)2·2H2O (1), was synthesized by slow evaporation of mixed ethano-lic solutions of CoCl2, benzene-1,3,5-tri-carb-oxy-lic acid (H3btc) and imidazole (Im) at room temperature. The crystal structure comprises [Co(Im)6]2+ cations, btc3- anions, Im+ cations and water mol-ecules in a 1:2:4:2 ratio. The crystal packing shows alternating layers stacked along the c-axis direction, linked primarily by hydrogen bonds of the types N-H⋯O (between cations and anions) and O-H⋯O (between anions and water mol-ecules).