Platinum(II)-Crosslinked Single-Chain Nanoparticles: An Approach towards Recyclable Homogeneous Catalysts

We introduce the synthesis and in-depth characterization of platinum(II)-crosslinked single-chain nanoparticles (Pt^II -SCNPs) to demonstrate their application as a recyclable homogeneous catalyst. Specifically, a linear precursor copolymer of styrene and 4-(diphenylphosphino)styrene was synthesized via nitroxide-mediated polymerization. The triarylphosphine ligand moieties along the backbone allowed for the intramolecular crosslinking of single chains via the addition of [Pt(1,5-cyclooctadiene)Cl₂ ] in dilute solution. The successful formation of well-defined Pt^II -SCNPs was evidenced by size exclusion chromatography, dynamic light scattering, nuclear magnetic resonance (¹ H, ³¹ P{¹ H}, ¹⁹⁵ Pt), and diffusion-ordered spectroscopy. Finally, the activity of the Pt^II -SCNPs as homogeneous, yet recyclable catalyst was successfully demonstrated using the example of the amination of allyl alcohol.