Sonochemical Synthesis of a Nanosized Coordination Polymer with Catalytic Activity for Selective Epoxidation of Olefins

Abstract

A three-dimensional coordination polymer, {(Mo 2 O 6 )(4,4'-bpy)} n (1) (4,4'-bpy = 4,4'-bipyridine), was synthesized under solvothermal conditions and characterized by single crystal X-ray diffraction analysis, powder X-ray diffraction (XRD), Fourier transformation infrared (FT-IR) spectroscopy and thermogravimetric analysis (TGA). The coordination polymer was also prepared in nanoscale via an ultrasound-assisted top-down process. The nanosized coordination polymer was characterized by means of scanning electron microscopy (SEM), XRD and FT-IR spectroscopy. The prepared oxomolybdate-based coordination polymer, in bulk and nanoscale, was applied as heterogeneous catalyst for the epoxidation of some olefins using tert-butyl hydroperoxide (TBHP) as oxidant. The 3-D coordination polymer, particularly in nanoscale, demonstrated good activity and stability in the epoxidation reaction and could be easily recovered and reused in the reaction.

Process Intensification and Catalysis

“…Examples of heterogeneous reactions promoted by ultrasound include selective reductions, 16,17,92 esterification, 93-95 transesterification, 96,97 advanced oxidation, 98,99 heterocyclizations, 100 epoxidation, 101 CdC coupling, 102 free radical polymerizations, 103 synthesis of sulphonamide. 104 Generic effects ascribable to the ultrasound-solid particle synergy include insertion/intercalation of guest molecules (reactant) into host nanoreactors, 105 desorption of the products, 22 cleaning and sweeping of the catalyst surface, thus preventing fouling, particle size reduction and increase of the specific surface area (SSA).…”