Silica encapsulated magnetic nanoparticles-supported Zn(II) nanocatalyst: A versatile integration of excellent reactivity and selectivity for the synthesis of azoxyarenes, combined with facile catalyst recovery and recyclability Original Research Article

A novel and highly efficient zinc based nanocatalyst has been synthesized by covalent grafting of 2-acetylpyridine on amine functionalized silica@magnetite nanoparticles, followed by metallation with zinc acetate. The resulting nano-composite was found to be highly efficient for oxidation of various aromatic amines to give azoxyarenes. The prepared nanocatalyst was characterized by Electron microscopy techniques (SEM and TEM with EDS), X-ray diffraction (XRD), vibrational sampling magnetometer (VSM), Fourier transform infrared spectroscopy (FT-IR) and atomic absorption spectroscopy (AAS) techniques. High turnover number (TON), mild reaction conditions and high selectivity for azoxyarenes with sustained catalytic activity makes present protocol worthy and highly compliant as compared to the other non-magnetic heterogeneous catalytic system. The acquisition of this nanocatalyst is also exemplified by employing the catalyst in leaching and reusability test and the results from the tests showing negligible zinc leaching and recycling was achieved multiple times just by sequestering using an external magnet.