Reaction of VOSO4·5H2O with a methanol solution of the HQ proligand (HQ = 1-R1-4-R2(C O)pyrazol-5-one. Characterized by elemental analyses, IR, ESI-MS, electronic spectroscopy and magnetic susceptibility measurements. and, in the case of derivative VO(QCF3)2, also by EPR spectroscopy. The catalytic activity of these new oxovanadium(IV) complexes has been exhaustively tested for the oxidation of styrene, methylstyrene and cis methylstyrene, in the presence of H2O2 as primary oxidant. The effects of oxidant to substrate molar ratio, catalyst amount, solvent and temperature have been studied. Overall, the vanadium complexes showed high activity and high to moderate selectivity toward the benzaldehyde (acetophenone) formation, depending from both the type of starting substrate and experimental reaction times.
Synthesis and characterization of novel oxovanadium(IV) complexes with 4-acyl-5-pyrazolone donor ligands: Evaluation of their catalytic activity for the oxidation of styrene derivatives
MARCHETTI, Fabio;PETTINARI, Claudio;DI NICOLA, CORRADO;PETTINARI, Riccardo;
2010-01-01
Abstract
Reaction of VOSO4·5H2O with a methanol solution of the HQ proligand (HQ = 1-R1-4-R2(C O)pyrazol-5-one. Characterized by elemental analyses, IR, ESI-MS, electronic spectroscopy and magnetic susceptibility measurements. and, in the case of derivative VO(QCF3)2, also by EPR spectroscopy. The catalytic activity of these new oxovanadium(IV) complexes has been exhaustively tested for the oxidation of styrene, methylstyrene and cis methylstyrene, in the presence of H2O2 as primary oxidant. The effects of oxidant to substrate molar ratio, catalyst amount, solvent and temperature have been studied. Overall, the vanadium complexes showed high activity and high to moderate selectivity toward the benzaldehyde (acetophenone) formation, depending from both the type of starting substrate and experimental reaction times.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
