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Use of water-soluble phosphine ligands in heterogeneous hydroformylation catalysis : application to long-chain 1-alkenes
The two-phase rhodium-tri(m-sulfonatophenyl)phosphine (Rh-TPPTS) system for the hydroformylation of 1-octene, 1-decene, and 1-dodecene to the corresponding aldehydes, has been investigated. Due to the two distinct phases - the catalytic species in the aqueous phase and the products and reactants in...
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| Format: | Thesis |
| Language: | English |
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Department of Chemistry
2016
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| _version_ | 1867613195912347648 |
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| access_status_str | Open Access |
| author | Du Toit, Judith G O |
| author2 | Koch, Klaus R |
| author_browse | Du Toit, Judith G O Koch, Klaus R |
| author_facet | Koch, Klaus R Du Toit, Judith G O |
| author_sort | Du Toit, Judith G O |
| collection | Thesis |
| description | The two-phase rhodium-tri(m-sulfonatophenyl)phosphine (Rh-TPPTS) system for the hydroformylation of 1-octene, 1-decene, and 1-dodecene to the corresponding aldehydes, has been investigated. Due to the two distinct phases - the catalytic species in the aqueous phase and the products and reactants in the organic phase - the separation of the catalyst was easily facilitated. A comparison was made of the activity, selectivity towards linear aldehydes, and catalyst lifetime of two systems where i) the active catalytic species were generated in situ from rhodium trichloride (RhCl₃.3H₂O) and excess phosphine ligand (TPPTS) under mild hydroformylation conditions (5 MPa H₂/CO (1:1); 100 °C); and ii) where the rhodium(I) complex, RhH(CO)(TPPTS)₃ is used as the catalyst precursor. The former system was found to be superior in activity and selectivity to that of the latter, achieving fairly high conversions of ca. 60% for the hydroformylation of 1-octene, with n:iso ratios of up to 16:1 for a catalyst composition a Rh:P ratio of 1:30. Unfortunately low conversions of ca. 10% for the hydroformylation of 1-decene and ca. 4% for that of 1-dodecene resulted under the same conditions. While the reasons for the drastic decrease in conversion for C₁₀ and C₁₂ alkenes is not completely clear, this poor conversion is attributed to the extremely low solubility of the long-chain 1-alkenes in the aqueous phase. Under certain optimum conditions (Rh:P ≥ l :20), virtually no leeching of rhodium into the organic phase was detected. A ³¹P NMR spectroscopic study was undertaken in an attempt to ascertain the nature and distribution of rhodium tertiary-phosphine complexes in the aqueous phase before and after the mixture was subjected to standard hydroformylation conditions. |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/22055 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:32:17.361Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2016 |
| publishDateRange | 2016 |
| publishDateSort | 2016 |
| publisher | Department of Chemistry |
| publisherStr | Department of Chemistry |
| record_format | dspace |
| source_str | UCTD — University of Cape Town Open Access Repository |
| spelling | oai:open.uct.ac.za:11427/22055 Use of water-soluble phosphine ligands in heterogeneous hydroformylation catalysis : application to long-chain 1-alkenes Du Toit, Judith G O Koch, Klaus R Chemistry The two-phase rhodium-tri(m-sulfonatophenyl)phosphine (Rh-TPPTS) system for the hydroformylation of 1-octene, 1-decene, and 1-dodecene to the corresponding aldehydes, has been investigated. Due to the two distinct phases - the catalytic species in the aqueous phase and the products and reactants in the organic phase - the separation of the catalyst was easily facilitated. A comparison was made of the activity, selectivity towards linear aldehydes, and catalyst lifetime of two systems where i) the active catalytic species were generated in situ from rhodium trichloride (RhCl₃.3H₂O) and excess phosphine ligand (TPPTS) under mild hydroformylation conditions (5 MPa H₂/CO (1:1); 100 °C); and ii) where the rhodium(I) complex, RhH(CO)(TPPTS)₃ is used as the catalyst precursor. The former system was found to be superior in activity and selectivity to that of the latter, achieving fairly high conversions of ca. 60% for the hydroformylation of 1-octene, with n:iso ratios of up to 16:1 for a catalyst composition a Rh:P ratio of 1:30. Unfortunately low conversions of ca. 10% for the hydroformylation of 1-decene and ca. 4% for that of 1-dodecene resulted under the same conditions. While the reasons for the drastic decrease in conversion for C₁₀ and C₁₂ alkenes is not completely clear, this poor conversion is attributed to the extremely low solubility of the long-chain 1-alkenes in the aqueous phase. Under certain optimum conditions (Rh:P ≥ l :20), virtually no leeching of rhodium into the organic phase was detected. A ³¹P NMR spectroscopic study was undertaken in an attempt to ascertain the nature and distribution of rhodium tertiary-phosphine complexes in the aqueous phase before and after the mixture was subjected to standard hydroformylation conditions. 2016-10-03T04:10:05Z 2016-10-03T04:10:05Z 1994 Master Thesis Masters MSc http://hdl.handle.net/11427/22055 eng application/pdf Department of Chemistry Faculty of Science University of Cape Town |
| spellingShingle | Chemistry Du Toit, Judith G O Use of water-soluble phosphine ligands in heterogeneous hydroformylation catalysis : application to long-chain 1-alkenes |
| thesis_degree_str | Master's |
| title | Use of water-soluble phosphine ligands in heterogeneous hydroformylation catalysis : application to long-chain 1-alkenes |
| title_full | Use of water-soluble phosphine ligands in heterogeneous hydroformylation catalysis : application to long-chain 1-alkenes |
| title_fullStr | Use of water-soluble phosphine ligands in heterogeneous hydroformylation catalysis : application to long-chain 1-alkenes |
| title_full_unstemmed | Use of water-soluble phosphine ligands in heterogeneous hydroformylation catalysis : application to long-chain 1-alkenes |
| title_short | Use of water-soluble phosphine ligands in heterogeneous hydroformylation catalysis : application to long-chain 1-alkenes |
| title_sort | use of water soluble phosphine ligands in heterogeneous hydroformylation catalysis application to long chain 1 alkenes |
| topic | Chemistry |
| url | http://hdl.handle.net/11427/22055 |
| work_keys_str_mv | AT dutoitjudithgo useofwatersolublephosphineligandsinheterogeneoushydroformylationcatalysisapplicationtolongchain1alkenes |