Synthesis and characterization of cobalt(II) chelates of N,N '-ethylene bis-salicylaldimine and related quadridentate ligands

Cobalt(II) complexes with a series of as many as sixteen SALEN type of quad ridentate ligands derived by condensing substituted carbonyls and different diamines have been synthesized and characterized by IR, N-1 NMR; molar con ductivity, magnetic susceptibility measurements and electronic spectral dat a. Subnormal magnetic moment values infer the presence of dimeric structure for the present complexes. However, electronic spectral data suggest a squ are planar structure in solution, possibly due to the monomeric structure. Infrared spectral data suggest the bonding of ligands through two ortho phe nolic oxygen and two azomethine nitrogen atoms. The electrochemical behavio ur of these complexes has been studied by cyclic voltammetry. Additional ph enolic groups present in these complexes are useful for the facile synthesi s of polymer supported cobalt complexes.