Highly active and selective catalysts for olefin hydrosilylation reactions using metalloporphyrins intercalated in natural clays

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Journal Title, Volume, Page: 
Reaction Chemistry and Engineering (Royal Society of Chemistry) Invited Paper ,1
Year of Publication: 
Waheed Jondi, Ahed Zyoud, Waseem Mansour, Ahmad Q Hussein, Hikmat S. Hilal
Preferred Abstract (Original): 

 Tetra(-4-pyridyl)porphyrinato-manganese(III) (MnTPyP+ ions) intercalated inside nano- and micro-size natural clay powders effectively catalyzed the hydrosilylation reaction of 1-octene and tri(ethoxy)silane under mild conditions. The results showed that the homogeneous MnTPyP+ ions catalyzed the reaction where both branched and linear products were observed. Intercalation significantly enhanced both catalyst activity and selectivity. Production of the linear tri(ethoxy)silyl-1-octane as sole product was confirmed by FT-IR and NMR spectra, in case of the intercalated catalyst. The activity enhancement was more pronounced in case of the nano-particle supported catalyst system, with turn-over frequency (TF) values up to 1200 min-1 and 85% conversion observed in less than 20 min. The intercalated catalyst systems were easy to recover and re-use for three times, while retaining up to 80% of their original activity. Effects of different reaction parameters on the initial reaction rate, such as clay particle size, solvent polarity, reactant concentration, catalyst loading and temperature were investigated. A new plausible mechanism, with evidences and justifications, is proposed.