Development of multi-metallic complexes using metal-salen complexes as building blocks

Metal-salen complexes have been widely used in inorganic chemistry to synthesize polynuclear complexes. This review highlights the synthetic strategy of multi-metallic complexes using metal-salen complexes as building blocks and structures of the resulting complexes. Three different processes have been used to prepare multi-metallic complexes using metal-salen complexes: (i) use of metal-salen complexes as metalloligands, (ii) self-assembly processes involving [M(salen)] complexes and various cyanaometallates and (iii) use of salen-type compartmental ligands. Complexes formed by these methods are included in the review. X-ray single crystal diffraction analysis confirmed the structures of these complexes. The properties of these complexes are also briefly discussed. This review will be of interest to researchers and synthetic chemists for synthetic strategy of homo- and heterometallic polynuclear complexes using salen-type Schiff bases.