Pd-complex driven formation of single-chain nanoparticles?

Polymer Chemistry Pub Date: 2015-04-23 DOI: 10.1039/C5PY00389J

Abstract

We report the facile synthesis of well-defined palladium(II) cross-linked single-chain nanoparticles (Pd-SCNPs) using the ‘repeating unit approach’. The linear precursor polymer (Mn ≈ 10?200 g mol?1, ? ≈ 1.17) was synthesized via nitroxide mediated statistical copolymerization of styrene and 4-(chloromethyl)styrene (CMS) followed by a post-polymerization modification of the resulting copolymer to covalently attach the triarylphosphine ligand moieties. The ligand content along the lateral polymer chain was 12%. Intramolecular crosslinking was performed in diluted solution with a suitable precursor complex (Pd[1,5-cyclooctadiene]Cl2) to afford the well-defined Pd-SCNPs, which feature a hydrodynamic diameter of Dh = 5.4 nm. The palladium(II) containing single-chain nanoparticles were characterized in-depth using 1H NMR spectroscopy, 31P{1H} NMR spectroscopy, dynamic light scattering (DLS), size exclusion chromatography (SEC), 1H spin–spin relaxation time (T2) analysis, X-ray photoelectron spectroscopy (XPS), and log-normal distribution (LND) simulations. Finally, the applicability of the Pd-SCNPs as catalyst in the Sonogashira coupling was exemplified.

Graphical abstract: Pd-complex driven formation of single-chain nanoparticles
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