A comparison of the coordination geometries of some 4-methylimidazole-5-carbaldehyde complexes with Zn(II), Cd(II) and Co(II) ions in the solid state and aqueous solution

Reactions of Zn(II), Cd(II) and Co(II) ions with 4-methylimidazole-5-carbaldehyde afforded four novel complexes. The compounds were characterized by X-ray diffraction, establishing tetrahedral, distorted dodecahedral and octahedral coordinating geometries of the Zn(II), Cd(II) and Co(II) metal ions, respectively. In solution, NMR and potentiometric methods have confirmed the preference of the central ions not only to adopt a specific coordination number and geometry of the coordination polyhedra, but also the function of the ligands which can be either monodentate or bidentate.