Synthesis of Molybdenum Chelate-Bonded Fe 3 O 4 Nanoparticles and Their Efficient Catalytic Activity in Epoxidation of Alkenes

Immobilization of Mo(VI) ions on magnetic nanoparticles has been performed using surface modification of Fe 3 O 4 with 2-hydroxy-5-(2-nitrophenyldiazenyl)benzaldehyde (HNPABA). The new nanomagnetic-supported organocatalyst (Fe 3 O 4 @SiO 2 −HNPABA−Mo(VI)) has been applied in epoxidation of olefins with tert -butyl hydroperoxide. The results indicate that Fe 3 O 4 @SiO 2 −HNPABA−Mo(VI) magnetic nanoparticles demonstrate excellent activity and high stability. The effect of several parameters such as a solvent, catalyst, oxidant content, and temperature has been studied. In addition, the catalyst could be repeatedly applied up to five times without loss of activity in epoxidation of alkenes.