Chloridobis[2-(1,5-dimethyl-1H-pyrazol-3-yl-κN 2)-1-methyl-1H-imidazole-κN 3]copper(II) chloride methanol hemisolvate tetrahydrate

In the title compound, [CuCl(C9H12N4)2]Cl·0.5CH3OH·4H2O, the CuII ion adopts a distorted trigonal-bipyramidal coordination arising from two bidentate ligands and a Cl− anion. The two heterocyclic ligands are planar with dihedral angles of 3.4 (1) and 0.7 (1)° between the pyrazole and imidazole rings. In the crystal, water molecules and uncoordinated chloride anions form an O—H⋯Cl and O—H⋯O hydrogen-bonded sheet parallel to (100) which lies between two layers of complex molecules. The packing is further stabilized by C—H⋯Cl and C—H⋯O hydrogen bonds. The methanol solvent molecule is disordered across a centre of inversion.

In the title compound, [CuCl(C 9 H 12 N 4 ) 2 ]ClÁ0.5CH 3 OHÁ4H 2 O, the Cu II ion adopts a distorted trigonal-bipyramidal coordination arising from two bidentate ligands and a Cl À anion. The two heterocyclic ligands are planar with dihedral angles of 3.4 (1) and 0.7 (1) between the pyrazole and imidazole rings. In the crystal, water molecules and uncoordinated chloride anions form an O-HÁ Á ÁCl and O-HÁ Á ÁO hydrogen-bonded sheet parallel to (100) which lies between two layers of complex molecules. The packing is further stabilized by C-HÁ Á ÁCl and C-HÁ Á ÁO hydrogen bonds. The methanol solvent molecule is disordered across a centre of inversion.

Comment
The ability of biheterocycles to form stable and biochemically interesting complexes, with transition metals has prompted several researchers to test them in several areas: medicine (El-Khawass & Bistawroos, 1990, Trofimenko, 1993, agriculture (Tsuboi et al., 1994, Hartfiel et al., 1993 and the photography industry (Allen & Wilson, 1963;Pearson, 1975). To contribute to the understanding of interaction of these heterocyclic compounds with transition metals, we have studied a copper complex of a biheterocycle prepared by Tjiou et al. (1989) and methylated using phase transfer catalysis process (Bouhaddioui, 1993).
In the crystal, the water molecules and uncoordinated chloride ions form a O-H···Cl and O-H···O hydrogen-bonded sheet parallel to the (100) and it lies between two layers of complex molecules. The packing is further stabilized by C-H···Cl and C-H···O hydrogen bonds (Table 2 and Fig.2).

Experimental
The title compound was synthesized by mixing a solution of biheterocycle in methanol and an aqueous solution of cupric chloride with a ligand/metal ratio of 2. Heating was maintained for few minutes until dissolution of all ligand. Then a pinch of NaCl was added and the heating was continued. When the solution became clear, it was left to stand at room temperature.
After a few days, green crystals were collected by filtration. They were dried over P 2 O 5 in a desiccator for 48 h.