Photochemical reactions of M(CO)5THF (M = Cr, Mo, W) with thio Schiff bases

The hitherto unknown complexes, [M2(CO)6(μ-CO)(μ-L)], [M = Cr; 1, Mo; 2, W; 3] and [M2(CO)6(μ-CO)(μ-L′)], [M = Cr; 4, Mo; 5, W; 6] have been synthesized by the photochemical reactions of photogenerated intermediate, M(CO)5THF (M = Cr, Mo, W) with thio Schiff base ligands, N,N′-bis(2-aminothiophenol)-1,4-bis(2-carboxaldehydephenoxy)butane (H2L) and N,N′-bis(2-aminothiophenol)-1,7-bis(2-formylphenyl)-1,4,7-trioxaheptane (H2L′). The complexes have been characterized by elemental analysis, LC-mass spectrometry, magnetic studies, FT-IR and 1H NMR spectroscopy. The spectroscopic studies show that H2L and H2L′ ligands are converted to benzothiazole derivatives, L and L′ after UV irradiation and coordinated to the central metal as bridging ligands via the central azomethine nitrogen and sulphur atoms in 1–6.