Synthesis of polymer-supported dendritic palladium nanoparticle catalysts for Suzuki coupling reactionReport as inadecuate




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Applied Nanoscience

, Volume 2, Issue 3, pp 211–222

First Online: 07 April 2012Received: 23 November 2011Accepted: 06 March 2012

Abstract

New bead-shaped heterogeneous nanoparticle catalysts viz., amino-terminated polyamidoamine PAMAM grafted on polystyrene-co-Polyvinylbenzylchloride PS-PolyVBC matrices immobilized-stabilized with palladium nanoparticle were prepared by simplified procedure. The first step is the preparation of PS-PolyVBC beads by suspension polymerization method. Second, the PAMAM G0 G1 and G2 dendrimers were grafted individually onto the PS-PolyVBC matrices via divergent method by repeating two reactions, i.e., Michael addition of methyl acrylate to surface amino groups of aminomethylated PS-PolyVBC matrixes followed by amidation of the resulting esters with ethylene diamine. The resulting three types of PAMAM G0, G1 and G2 grafted on PS-PolyVBC matrices were complexed individually with PdCl2 and thus yielded the corresponding new bead-shaped heterogeneous nanoparticle catalyst immobilized with PdNPs. The appearance of surface plasmon resonance band noticed at 547 nm in UV confirms the formation of PdNPs. The SEM result shows that the intensity of white patches due to immobilization of PdNPs increases with generation number and XRD reveals that the crystalline nature was decreased against generation number of the PAMAM. The catalytic efficiency of PS-PolyVBC-NH2-PdNPs-G0, G1 and G2 catalysts were examined by Suzuki coupling reaction performed in mixture of water-ethanol. The observed reaction yield reveals that the activity was proportional to the generation number of PAMAM grafted onto the PS-PolyVBC matrices. The percentage of reaction yield biphenyl is sustained to ≈70 % even up to five cycles and this in turn confirms the stability of the catalysts. These catalysts can be used to conduct the Suzuki-coupling reaction in continuous mode operation in industrial scale.

KeywordsHeterogeneous nanocatalyst Palladium nanoparticle Polystyrene supports Suzuki-coupling reaction Polyamidoamine dendrimer  Download fulltext PDF



Author: Eagambaram Murugan - J. Nimita Jebaranjitham - A. Usha

Source: https://link.springer.com/







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