Investigations of Complexes of Copper(II) Chloride with Phenylpyrazoles

The crystal structures of dichlorobis(3,5-diphenylpyrazole-N²)copper(II), [CuCl₂(C₁₅H₁₂N₂)₂], (I), dichlorobis(5-phenylpyrazole-N²)copper(II), [CuCl₂(C₉H₈N₂)₂], (II), and dichlorobis(1-phenylpyrazole-N²)copper(II), [CuCl₂(C₉H₈N₂)₂], (III), have been determined from X-ray diffraction data. There are significant differences in the coordination of the Cl^- ions to the Cu²⁺ ion. The coordination of the Cu²⁺ ion is distorted square pyramidal in compounds (I) and (II), and distorted tetrahedral in (III). All available N-H groups form hydrogen bonds, which are intra- and intermolecular in (I), and intramolecular in (II). An N-H group in (I) forms a bifurcated hydrogen bond. Intermolecular intereactions between neighbouring molecules form dimers and chains in (I) and (II), respectively.

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