Acta Phys. -Chim. Sin. ›› 2006, Vol. 22 ›› Issue (04): 465-469.doi: 10.3866/PKU.WHXB20060415

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Hydroformylation of Long-chain Olefins Catalyzed by Rhodium-Phosphine Complexes in New Ionic Liquids

LIN Qi;FU Hai-Yan;XUE Fang;YUAN Mao-Lin;CHEN Hua;LI Xian-Jun   

  1. Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, P. R. China; Department of Chemistry and Chemical Engineering, Minjiang University, Fuzhou 350108, P. R. China
  • Received:2005-11-15 Revised:2005-12-05 Published:2006-04-10
  • Contact: CHEN, Hua E-mail:scuhchen@163.com

Abstract: Preparation and characterization of a series of halogen-free ionic liquids 1-alkyl-3-methyl-imidazolium p-tolusulfonate([Rmim][p-CH3C6H4SO3], R= n-butyl, n-octyl, n-dodecyl, n-cetyl) were reported. These halogen-free ionic liquids were applied as a reaction medium in the hydroformylation catalyzed by water-soluble rhodium complex HRh(CO)(TPPTS)3[TPPTS: P(m-C6H4SO3Na)3]. The results showed that the activity of the hydroformylation was related with the chain-length of R-group in ionic liquids [Rmim][p-CH3C6H4SO3] and decreased with the increase of chain-length of higher olefins. Compared with the halogen-containing anologues [Bmim]BF4 and [Bmim]PF6, the hydroformylation of higher olefins in ionic liquids [Rmim][p-CH3C6H4SO3] exhibited higher activity and selectivity for the aldehydes. Under moderate reaction conditions, the catalyst turnover frequency of 1-hexene hydroformylation as high as 2736 h-1 has been observed. Moreover, the products were conveniently separated from the catalyst by simple decantation and the rhodium-phosphine complexes immobilized in the ionic liquids could be reused several times without significant loss of activity and selectivity. The rhodium leaching into the organic product was lower than 0.1%.

Key words: Ionic liquid, Hydroformylation, Water-soluble rhodium complexes, Synthesis