Immobilization of Rh(PPh3)3Cl on phosphinated MCM-41 for catalytic hydrogenation and hydroformylation of olefins

Institute of Chemistry, Academia Sinica* Institute of Bioscience and Biotechnologym, National Taiwan Ocean University**
â—‹Shin-Guang Shyu* Hsiu-Mei Lin** Der-Lii Tzou* Shequ-Wen Cheng*

The complex Rh(PPh3)3Cl immobilized on MCM-41 modified with (OEt)3Si(CH2)3PPh2 results in a stable hydrogenation catalyst with turn over frequency (TOF) three times higher than that of Rh(PPh3)3Cl in the hydrogenation of cyclohexene. Powder X-ray, BET pore size measurement and solid state 29Si NMR were used to characterize the morphology of the catalyst. Solid state 31P NMR and EXAFS analyses of Rh were carried out to investigate the structure of the immobilized Rh catalyst. EXAFS analyses show a Rh to Rh interaction at 3.0 Å indicating a possible dimmer structure without Rh-Rh metal-metal bonding. After hydrogenation, a Rh-Rh interaction at 2.6 Å was observed indicating the presence of a Rh-Rh metal-metal bonding.