کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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67537 | 48486 | 2008 | 7 صفحه PDF | دانلود رایگان |
The preparation of a new surface-active sulfonated phosphine and its catalytic performance in aqueous biphasic hydroformylation of long chain olefins were reported. The amphiphilic phosphine: sodium salt of sulfonated n-C12H25O C6H4P(C6H4-p-CH3O)2 (DMOPPS) was prepared by sulfonation of the hydrophobic phosphine DMOPP in concentrated H2SO4 under N2 atmosphere at 30 °C for about 5 h. The rhodium complex, RhCl(CO)(TPPTS)2 [TPPTS =P(C6H4-m-SO3Na)3], was used as the catalyst precursor. The catalytic active species with the DMOPPS as ligand was in situ formed by adding DMOPPS to the RhCl(CO)(TPPTS)2 catalyst precursor. The surface-activity and micelle-forming property of this new amphiphilic phosphine were confirmed by using cryogenic transmission electron microscope (Cryo-TEM). Under the same conditions, the biphasic hydroformylation of 1-decene using DMOPPS as ligand was compared with that using traditional TPPTS as ligand. The catalysis system using DMOPPS was also compared with the previous Rh-TPPTS-surfactant [C12H25N(CH3)3I (DTAI)] system. Some reaction parameters such as stirring rates, alkyl chain length of olefins, the molar ratio of phosphine/rhodium, and the catalyst recycle were also studied in detail. The results showed that the ligand DMOPPS exhibited a micelle-forming property that could significantly enhance the hydroformylation reaction rate of long chain olefin. Moreover, the surface-active phosphine may also stabilize the aqueous/oil phase boundary, which could enhance the biphasic catalytic reaction rates.
The preparation of a new surface-active phosphine-sodium salt of sulfonated n-C12H25OC6H4P(C6H4-p-CH3O)2 (DMOPPS) and its application in the aqueous biphasic catalytic hydroformylation of long chain olefins were reported. The ligand exhibits a surface-active property which could significantly enhance the reaction rate. Compared with previous RhCl(CO)(TPPTS)2–TPPTS-surfactant system, the RhCl(CO) (TPPTS)2–DMOPPS system shows better catalytic performances.Figure optionsDownload as PowerPoint slide
Journal: Journal of Molecular Catalysis A: Chemical - Volume 292, Issues 1–2, 17 September 2008, Pages 21–27