Sonochemically activated room temperature hydrosilylation of silicon nanoparticles

Hydrosilylation of terminal alkenes and alkynes on the surfaces of hydrogen-terminated silicon nanoparticles (H-SiNPs) has provided a convenient approach toward tailoring surface chemistry. These reactions have traditionally required thermal, photochemical, or chemical activation and are not necessarily compatible with all substrates and particle sizes. Herein, we demonstrate that hydrosilylation on silicon nanoparticles (Si NPs) can be promoted at room temperature by exposing the reaction mixture to a standard ultrasonic bath. This new approach provides surface coverages approaching 30% after 24 h. Introduction of traditional radical initiators to the reaction mixture followed by sonication reduced the reaction time by approximately 4-fold. The Si NPs functionalized using the presented sonochemical methods were compared with equivalent systems modified using conventional thermally- and radically-induced procedures and retain their appealing photoluminescent properties and were found to have slightly lower (i.e., 27 vs. 33%), albeit comparable degrees of functionalization.