Synthesis, characterization, crystal structures, and catalytic property of dioxomolybdenum(VI) complexes derived from similar benzohydrazone derivatives

Abstract

ABSTRACTA pair of new dioxomolybdenum(VI) complexes, [MoO2L1(CH3OH)] (1) and [MoO2L2(CH3OH)] (2), where L1 and L2 are the dianionic forms of 5-bromo-N′-(2-hydroxy-3-methoxybenzylidene)benzohydrazide and N′-(2-hydroxy-3-methoxybenzylidene)-3-methylbenzohydrazide, respectively, have been synthesized and characterized by elemental analysis, FT-IR spectra, and single crystal X-ray determination. The crystal of 1 is triclinic: space group P−1, a = 7.779(2), b = 10.002(3), c = 12.012(3) Å, α = 93.612(2), β = 93.252(2), γ = 105.798(2)°, V = 894.9(4) Å3, Z = 2, R1 = 0.0536, wR2 = 0.0938. The crystal of 2 is triclinic: space group P−1, a = 7.830(2), b = 10.000(3), c = 11.842(3) Å, α = 92.795(2), β = 94.168(2), γ = 103.692(2)°, V = 896.4(4) Å3, Z = 2, R1 = 0.0293, wR2 = 0.0764. The Mo atoms in the complexes are coordinated by one phenolate O, one imine N, and one enolic O atoms of the benzohydrazone ligand, two oxo O atoms, and one methanol O atom, forming octahedral coordination. In the crystal structures, adjacent two complex molecules are linked by two methanol ligands through intermolecular O−H···N hydrogen bonds, forming dimers. The catalytic property of sulfoxidation for the complexes was studied.