Synthesis, Characterization, and Crystal Structures of Dioxomolybdenum(VI) Complexes Derived from Similar Tridentate Hydrazone Compounds with Catalytic Property

Two hydrazone compounds 2-chloro-N'-(2-hydroxy-4-methoxybenzylidene)benzohydrazide (H2L1) and N'-(2-hydroxy-4-methoxybenzylidene)-3-methylbenzohydrazide (H2L2) were prepared and characterized by IR, UV-Vis and H-1 NMR spectra. Based on the hydrazone compounds, two new structurally similar dioxomolybdenum(VI) complexes, [MoO2L1(CH3OH)] (I) and [MoO2L2(CH3OH)] (II), were prepared and characterized by IR and UV-Vis spectra, and single crystal X-ray diffraction (CIF files nos. 1566491 (I) and 1566492 (II)). Complex I crystallizes as the triclinic space group Pwith unit cell dimensions a = 8.0750(5), b = 10.5223(7), c = 10.8110(7) angstrom, = 96.975(2)degrees, = 97.909(2)degrees, = 104.497(2)degrees, V = 869.2(1) angstrom(3), Z = 2, R-1 = 0.0323, wR(2) = 0.0620, GOOF = 1.089. Complex II crystallizes as the monoclinic space group P2(1)/n with unit cell dimensions a = 11.680(1), b = 10.496(2), c = 14.879(2) angstrom, = 98.862(2)degrees, V= 1802.2(4) angstrom(3), Z = 4, R-1 = 0.0270, wR(2) = 0.0675, GOOF = 1.111. X-ray analysis indicates that the complexes are mononuclear dioxomolybdenum(VI) species with the Mo atoms in octahedral coordination. The complexes were studied for their catalytic oxidation property on some olefins with tert-butyl hydrogen peroxide as oxidant.