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 (PtII‐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 PtII‐SCNPs was evidenced by size exclusion chromatography, dynamic light scattering, nuclear magnetic resonance (1H, 31P{1H}, 195Pt), and diffusion‐ordered spectroscopy. Finally, the activity of the PtII‐SCNPs as homogeneous, yet recyclable catalyst was successfully demonstrated using the example of the amination of allyl alcohol.