Synthesis and Characterization of Zn_(1-x)Ni_xAl₂O₄Spinels as a New Heterogeneous Catalyst of Biginelli's Reaction

Abstract

<TEX>$Zn_{(1-x)}Ni_xAl_2O_4$</TEX> (x = 0.0-1.0) spinels were prepared at <TEX>$800^{\circ}C$</TEX> by co-precipitation method and characterized by infrared spectroscopy, X-ray diffraction, scanning electron microscopy and X-ray photoelectron spectroscopy. The specific surface area was determined by BET. SEM image showed nano sized spherical particles. XPS confirmed the valence states of the metals, showing moderate Lewis character for the surface of materials. The powders were successfully used as new heterogeneous catalysts of Biginelli's reaction, a one-pot three-component reaction, leading to some dihydropyrimidinones (DHPMs). These new catalysts that produced good yields of DHPMs, were easily recovered by simple filtration and subsequently reused with persistent activity, and they are non-toxic and environmentally friendly. The optimum amount of catalyst is 20% by weight of benzaldehyde derivatives, while the doping amount has been found optimal for x = 0.1.