Pt-Coated Silicon Nanoparticles: An Investigation into the Hydrosilylation on Hydrogen-Terminated Silicon Surfaces Using Pt(dvs).

The interaction of hydrogen-terminated silicon nanoparticles (H-SiNPs) with Karstedt's catalyst at various temperatures was investigated. The results indicate that at room temperature, the oxidative addition of Pt(0) onto H-SiNPs is irreversible, and the catalyst is not eliminated from the surface of H-SiNPs, enabling a facile synthesis of Pt-loaded SiNPs that can undergo ligand exchange. The nature of the Pt-on-Si ensemble is characterized by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, and energy-dispersive X-ray spectroscopy. Reaction conditions that enable effective hydrosilylation are discussed. It is found that higher temperatures favor reductive elimination of the catalyst and hydrosilylation of 1-octene onto the surface of the H-SiNPs.

Si-H Surface Groups Inhibit Methacrylic Polymerization: Thermal Hydrosilylation of Allyl Methacrylate with Silicon Nanoparticles.

Hydrogen-terminated silicon nanoparticles (H-SiNPs) inhibit anerobic thermal autopolymerization of methacrylates. When heated to 100 °C under an inert atmosphere, allyl methacrylate (AMA) was stable for at least 95 h in the presence of 1.2 wt % H-SiNPs, exhibiting less than 0.15% conversion, whereas the neat monomer solidified within 24 h (over 10% conversion after 34 h). A mechanism is proposed that is based on H-transfer from SiNPs to the thermally activated methacrylic dimer biradical, quenching autopolymerization. An analysis of SiNPs isolated after heating in AMA reveals the grafting of ester groups. Thermal hydrosilylation offers a facile way to attach an allyl group to the surface of SiNPs.