Synthesis and characterization of tetrahedral and square planar bis(iminopyrrolyl) complexes of cobalt(II)

The synthesis and characterization of a series of [[Co.sup.II](iminopyrrolyl)2] complexes in which the bidentate chelating ligands encompass increasing bulkiness is discussed. DFT calculations suggest that the square planar geometry is slightly more stable than the tetrahedral one due to a combination of steric and electronic reasons.