Epoxidation of stilbene using supported gold nanoparticles: cumyl peroxyl radical activation at the gold nanoparticle surface.

The catalytic epoxidation of cis-stilbene using cumene as a solvent in the presence of supported gold nanoparticles (AuNP) yields a mixture of cis and trans-stilbene oxides. EPR and product distribution studies support a new mechanistic proposal where oxygen centred radicals activate the AuNP surface and form active surface oxygen species responsible for the epoxidation products.

Size-controlled photochemical synthesis of niobium nanoparticles.

The size of photochemically-prepared niobium nanoparticles (NbNP) can be controlled by varying the concentration of the photoinitiator in the reaction mixture. The particles, which may be metallic in nature, are readily oxidized upon air exposure to form stable niobium(v) oxide nanoparticles (NbONP) that act as strong Brønsted acids.