Cobalt(II) complexes of pyridazine or triazole containing ligands: spin-state control

Structurally characterised cobalt(II) complexes containing pyridazine, triazole or triazolate ligands are the subject of this review. Firstly a brief introduction to Schiff-base macrocyclic chemistry is given and then the crystal structures and magnetic properties of pyridazine-containing cobalt(II) complexes are discussed, focussing on macrocyclic complexes. There follows a discussion of the crystal structures, as well as the magnetic behaviour where known, of cobalt(II) complexes containing the triazole moiety in a N-1,N-2-bridging fashion. Finally an overview of reported complexes where the triazole unit has been incorporated into a Schiff-base macrocyclic framework is provided. None of these triazole-containing macrocyclic complexes has been structurally characterised. (C) 2003 Elsevier B.V. All rights reserved.