Photochemical reactions of group 6 metal carbonyls with N-salicylidene-2-hydroxyaniline and bis-(salicylaldehyde)phenylenediimine

Sunlight irradiation of the reactions of [M(CO)6], M=Cr, Mo and W with either N-salicylidene-2-hydroxyaniline (shaH2) or bis-(salicylaldehyde) phenylenediimine (salphenH2) in THF were investigated. Three complexes with molecular formulas [Cr(shaH2)3], 1, [MoO2(shaH2)2], 2, and [W2O5(shaH)2], 3 were isolated from the reactions with shaH2. The corresponding reactions with salphenH2 produced the oxo complexes [CrO(salphenH2)], 4, [Mo2O6(salphenH2)2], 5, and [W2O6(salphenH2)], 6. All complexes were characterised by elemental analysis, infrared, mass and 1H NMR spectroscopy. The UV-vis spectra of the complexes in different solvents showed visible bands due to either ligand-to-metal or metal-to-ligand charge transfer. Thermal properties of the complexes were investigated by TG thermogravimetry technique.