Wydział Chemii

Ewa Mieczyńska

Anna M. Trzeciak

Ryszard Grzybek

Józef J. Ziółkowski

1998

Journal of Molecular Catalysis A-Chemical

132

203-212

10.1016/S1381-1169(97)00244-6

Naukowa

Angielski

Artykuł

The catalytic activity of rhodium complexes formed in reactions of catalyst precursor, [Rh(acac)(CO)₂] with water soluble phosphines: Ph₂PCH₂CH₂CONHC(CH₃)₂CH₂SO₃Li (PNS), Ph₂PCH₂CH(COOLi)(CH₂COOLi) (PC), Ph₂PCH₂CH(CH₃)(COOH) (PH) or Ph₂PCH₂CH(CH₃)(COONa) (PNa) in hydrogenation and hydroformylation of 1-hexene in mono- and biphasic systems have been studied. The yield of aldehydes obtained in hydroformylation of 1-hexene in the system [Rh(acac)(CO)₂]+PNS strongly depends on the kind of solvent: 24% in toluene, 53–86% (n/iso 2.9–4.6) in the toluene–water–ethanol mixture and 77–94% (n/iso 2.5–3.8) in water–ethanol solution. The mixture of water–ethanol as a solvent was also found to be the best for hydrogenation of 1-hexene (96% of hexane) with [Rh(acac)(CO)₂]+PNS system. Application of PH phosphine (in hydrogen form) produces ca. 2% of aldehydes in both solvents, toluene only and toluene–water mixture. However, conversion of PH phosphine into its sodium salt, PNa, increased the catalytic activity of rhodium catalyst up to 85% yield of aldehydes in toluene, 92% in toluene–water and 94% in toluene–water–ethanol mixture. Spectroscopic studies of the reaction mixture in situ (IR, -, -NMR) allowed to identify following rhodium complexes existing in hydroformylation reaction conditions in the system [Rh(acac)(CO)₂]+PH/PNa: [Rh(acac)(CO)(PH)], [Rh(OH)(CO)(PH)₂], [HRh(CO)(PNa)₃], [Rh₄(CO)_12−x(PH)_x]. [HRh(CO)(PNa)₃] was found to be stable only when sodium hydroxide was introduced to the system.

Rhodium, Hydrogenation, Hydroformylation, Biphasic system, Water soluble phosphines

https://doi.org/10.1016/S1381-1169(97)00244-6

http://www.elsevier.com