Cobalt(II), nickel(II), and copper(II) complexes of 2-methylimidazole

Abstract

The preparation and spectral and magnetic properties are reported for complexes of cobalt(II), nickel(II), and copper(II) with 2-methylimidazole (Mlz). The complexes (Mlz)₂CoX₂(X = Cl, Br, or I), (Mlz)₂NiX₂(X = Br or I), and (Mlz)₂CuX₂(X = Cl or Br) have tetrahedral structures whereas (Mlz)₂NiCl₂ has a polymeric octahedral structure. The structures of the ‘inner’ complexes (Mlz′)₂N (Mlz′= C₄H₅N₂; N = Ni, Co, or Cu) together with that of (Mlz)₄CuCl₂ are described. The complexes are compared with those of 2-methylpyridine and the differences discussed in terms of steric hindrance and basicity.