The Study Of Supported Platinum Complexes Catalysts For Hydrosilylation Reaction Of Alkenes

Hydrosilylation is one of the most important reaction, which is used widely. Many organic silicon compounds can be synthesized with this reaction. For example, phenethylmethyldichlorosilane is useful chemicals as si lane-coupling reagents. Selectivity is a very important consideration in the hydrosilylation of asymmetrical alkenes. Such as styrene and γ-chloropropene , the hydrosilylation gives α and β -addition products. Generally, hydrosilylation is performed in the liquid phase using a homogeneous catalyst such as Speier's catalyst. However, it s diffcult to separation of the catalyst. Using supported catalyst, which had both properties of homogeneous and heterogeheous catalysts for hydrosilylation, was one of the solutions for this problem. Thus, it's not surprising that effects to improve the efficiency and broaden the range of application of the supported catalysts and the process are ongoing.With the use of polyethylene glycol ligand, and the use of carrier such as silica, 5A zeolite, carbon nanotubes, these catalysts display higher catalytic activity and remarkably improve the selectivity β -addition products at room temperature under an atmospheric pressure and solvent-less for the hydrosilylation reaction of styrene with methyldichlorosilane. Reaction at 293K in air bath, using Pt-PEG/SiO₂ catalyst, the conversion of styrene reached 90.0% in 180min, the selectivity of β-addition products was 100%. Using Pt-3/SiO₂ catalyst at 293K, the conversion of styrene reached 93. 7% in 12 hour, the selectivity of α and β-addition products were 8.9% and 91.0% respectively. Using Pt-PEG/γ-Al₂0₃catalyst at 293K, the conversion of styrene reached 92.5% in 9 hour, the selectivity of β-addition products was 100%. Comparing these four catalysts, the reason of β-addition product high selectivity...