Cobalt(II), nickel(II), and copper(II) complexes of imidazole and thiazole

The preparation and spectral and magnetic properties are reported for the complexes of the type Co(imidazole)6X2 and Ni(imidazole)6X2(X = Cl, Br, l, or NO3) and Cu(imidazole)4X2(X = Cl or NO3). These compounds have octahedral or distorted octahedral structures whereas the compounds Co(imidazole)2Cl2 and di-imidazolatocobalt(II) are tetrahedral. The “inner” complex di-imidazolatonickel(II) has a square-planar structure. The thiazole complexes Ni(thiazole)4Cl2, Co(thiazole)2Cl2, and Cu(thiazole)2Cl2 are described and are shown to have essentially octahedral structures.