Polyaniline-Supported Zinc Oxide (ZnO) Nanoparticles: An Active and Stable Heterogeneous Catalyst for the Friedel–Crafts Acylation Reaction

Abstract

We report herein the synthesis of zinc oxide (ZnO) nanoparticles incorporating a polyaniline (PANI) matrix in aqueous medium and its catalytic performance toward Friedel–Crafts acylation reactions. The acylation reactions demonstrate that polyaniline/nano-ZnO composites are very active catalysts and are able to activate the reactant at ambient temperature. The obtained nanocatalyst was characterized by Fourier transform–infrared, scanning electron microscopy, transmission electron microscopy, Brunauer–Emmett–Teller, X-ray diffraction, and particle-size analysis techniques. The catalyst was reusable for five cycles without appreciable loss in activity.

GRAPHICAL ABSTRACT

Keywords:

• Friedel–Crafts acylation
• green synthesis
• heterogeneous catalyst
• polymer-supported
• zinc oxide nanoparticles

ACKNOWLEDGMENT

We gratefully acknowledge financial support from the Research Council of Shahid Beheshti University.

Notes

^a The reactions were carried out with 1 mmol of benzoyl chloride and 5 mmol of aromatic compound.

^b Isolated yields. The ratio of para/ortho-isomers was determined by ¹ H NMR.

^c The reactions were carried out with 1 mmol of benzoyl chloride and 2 mmol of aromatic compound.

^a Isolated yields. The ratio of para/ortho-isomers was determined by ¹ H NMR.