Palladium Nanoparticles Stabilized by Glycodendrimers and Their Application in Catalysis

Abstract

Abstract Palladium nanoparticles stabilized by glycodendrimers (PdDSNs) in water were prepared by coordination of Pd II to intradendritic triazole ligands upon reaction of K 2 PdCl 4 with the dendrimer in water followed by aqueous NaBH 4 reduction to Pd 0 . TEM images show that the PdDSNs are small (average diameter: 2.3 nm) and relatively monodisperse owing to a low concentration of metal precursor. The catalytic activity of these PdDSNs was evaluated for the reduction of 4‐nitrophenol (4‐NP) to 4‐aminophenol (4‐AP) by NaBH 4 (only 0.2 mol‐% of Pd per mol substrate is used) and for the Miyaura–Suzuki C–C coupling with various substituted aryl bromides (only 0.01 mol‐% of Pd per mol substrate is used). Comparisons of the catalytic activities of these PdDSNs with those of larger PdDSNs (diameter: 14 nm) reveal that smaller NPs catalyze faster 4‐NP reduction than their larger counterparts but lack any notable surface dependency for Suzuki–Miyaura catalysis.