Synthesis and characterization of some transition metal carbonyl complexes containing nitrogen and sulphur donor ligands

The hitherto unknown Schiff base-metal carbonyl complexes were synthesized by the photochemical reactions of photogenerated intermediate, M(CO)5THF (M = Cr, Mo, W) with four Schiff base ligands, N,N'-bis(2-aminothiophenol)-1,4-bis(2-carboxaldehydephenoxy)butane, N,N?-bis(2-aminothiophenol)-1,7-bis(2-formylphenyl)-1,4,7-trioxaheptane, N,N'-bis(2-hydroxynaphthalin-1-carbaldehydene)-1,2-bis(p-aminophenoxy)ethane and N,N'-bis(2-hydroxynaphthalin-1-carbaldehydene)-1,4-bis(p-aminophenoxy)butane.The complexes were characterized by elemental analysis, LC- mass spectrometry, magnetic studies, FTIR and 1H NMR spectroscopy.The spectroscopic studies show that N,N'-bis(2-aminothiophenol)-1,4-bis(2-carboxaldehydephenoxy)butane and N,N?-bis(2-aminothiophenol)-1,7-bis(2-formylphenyl)-1,4,7-trioxaheptane ligands are converted to benzothiazole derivatives after UV irradiation and coordinated to the central metal as bridging tetradentate ligands in addition to N,N'-bis(2-hydroxynaphthalin-1-carbaldehydene)-1,2-bis(p-aminophenoxy)ethane and N,N'-bis(2-hydroxynaphthalin-1-carbaldehydene)-1,4-bis(p-aminophenoxy)butane ligands are coordinated to the central metal as tetradentate ligands.Keywords: N,N'-bis(2-aminothiophenol)-1,4-bis(2-carboxaldehydephenoxy)butane, N,N?-bis(2-aminothiophenol)-1,7-bis(2-formylphenyl)-1,4,7-trioxaheptane, N,N'-bis(2-hydroxynaphthalin-1-carbaldehydene)-1,2-bis(p-aminophenoxy)ethane, N,N'-bis(2-hydroxynaphthalin-1-carbaldehydene)-1,4-bis(p-aminophenoxy)butane, metal carbonyls, Schiff base.