Synthesis of Nano Magnetite Fe3O4 Based Vanadic Acid: A Highly Efficient and Recyclable Novel Nanocatalyst for the Synthesis of 4,4'-(arylmethylene)-bis(3-methyl-1-phenyl-1H-pyrazol-5-ols).

Nano magnetic Fe3O4 based vanadic acid [MNPs@VO(OH)2] (average diameter 20-26 nm) has been synthesized by grafting VOCl3 on the Fe3O4 surface nanoparticles as a retrievable supporter to produce novel heterogeneous reusable solid acid with dual ability (Bronsted and Lewis acid) followed by stirring in the air. The resultant material was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) analysis and energy-dispersive X-ray spectroscopy (EDX). Significantly, the as-prepared [MNPs@VO(OH)2] exhibits a high catalytic activity in the synthesis of 4,4'-(arylmethylene)bis(3-methyl-1-phenyl-1H-pyrazol-5-ols). Additionally, the newly synthesized heterogeneous solid acid catalyst can be reused for several times without apparent loss of its catalytic activity. [ABSTRACT FROM AUTHOR]