Abstract
This communication reports the instability of tris(2,2′-bipyridine)cobalt(III) toward ligand substitution. 2,2′-Bipyridine(“bpy”) has been recognized as one of the most potent ligands and used to prepare many kinds of metal complexes. Nevertheless, one of the authors1 reported the preparation of [Co(CN)2(bpy)2]Cl, which was obtained by the reaction of [Co(bpy)3]3+ with cyanide ion in water. The reaction was reported to occur within five minutes at room temperature. The strong nucleophilicity of the cyanide ion might be responsible for this kind of substitution.