Coordination of 2,2'-Biimidazole with Iron, Cobalt, Nickel and Copper

Abstract

Complexes of 2,2'-biimidazole with bivalent iron, cobalt, nickel and copper, and trivalent iron are described. The ligand produces a relatively weak field and all complexes are high-spin and markedly less stable than corresponding complexes of 2,2'-bipyridine or 2-(2-pyridyl)imidazole. Inner complexes, M(L-H)₂, derived from the monoanion of biimidazole are also described. The complexes are characterized by magnetic and spectral data.