Peroxo- and oxovanadium(IV) complexes with tridentate N-heterocycle ligands: synthesis, structure, and catalytic performance

Three peroxo-and oxovanadium(IV) complexes: [VO(O-2)(bpz*eaT)center dot VO(C4H4O6)]center dot H2O (1), [VOSO4(bpz*eaT)]center dot C6H8O7 (2) (bpz*eaT = 2,4-bis(3,5-dimethyl-1H-pyrazol-1-yl)-6-diethylamino-1,3,5-triazine) and [VO(C12H8N2)-(C9H7NO3)]center dot CH3OH center dot 0.5H(2)O (3) were synthesized and characterized by elemental analysis, IR spectra, UV-Vis spectroscopy and single-crystal X-ray diffraction. In addition, the catalytic performances of complexes 1-3 and their starting materials (VO(acac)(2) and VOSO4) were studied by the reaction of cyclohexane (Cy) oxidation. It is found that complex 1 exhibited the highest catalytic activity (TON(cyclohexanol) = 220, TON(cyclohexanone) = 346, Conv. = 97.9%) with H2O2 as an oxidant and HNO3 as an additive at 24 h, 40 degrees C, indicating that it is a potential candidate catalyst to oxidize the Cy to cyclohexanol (CyOH) and cyclohexanone (CyO) under mild conditions.