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

ABSTRACT

A 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) ų, 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) ų, 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.

KEYWORDS:

• Catalytic property
• dioxomolybdenum
• benzohydrazone
• crystal structure
• hydrogen bonds

Funding

This research was supported by the National Sciences Foundation of China (No. 20676057 and 20877036) and Top-class foundation of Pingdingshan University (No. 2008010).