Synthesis and characterization of bifunctional lipophilic and basic mesoporous organosilica supported palladium nanoparticles as an efficient and ecofriendly nanocomposite in aqueous Heck reaction

摘要

In the present study, a highly ordered mesoporous organosilica nanocomposite having modified pore channels with both lipophilic and basic units, SBA-R/Im-NH2, was synthesized through surfactant-templated sol-gel methodology and post modification process. The nanocomposite with ionic liquid properties was used as a potential host for supporting palladium nanoparticles. The structure and composition of the target nanocomposite, SBA-R/Im-NH2 center dot Pd, were supported by infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), elemental analysis (CHNS), energy dispersive X-ray (EDX) and Brunauer-Emmett-Teller (BET) measurements. The efficiency of this porous inorganic-organic hybrid nanocomposite as a powerful catalyst in one of the most important carbon-carbon bond-forming process, the Heck coupling reaction of aryl halides with olefins, in aqueous media was also examined. This method has the advantages of high yields, cleaner reactions, simple methodology, short reaction times, easy workup, and greener conditions. In addition, the nanocatalyst can be easily separated from the reaction mixture and reused several times without significant decrease in activity and promises economic as well as environmental benefits.