Synthesis and characterization of dirhodium(II) formamidinyl complexes: preliminary studies as catalyst precursors for the allylic oxidation of cyclohexene
| dc.contributor.advisor | Ngubane, Siyabonga | |
| dc.contributor.advisor | Maestri, Giovanni | |
| dc.contributor.author | Casimiro, Anna | |
| dc.date.accessioned | 2019-02-22T11:29:19Z | |
| dc.date.available | 2019-02-22T11:29:19Z | |
| dc.date.issued | 2018 | |
| dc.date.updated | 2019-02-21T10:57:55Z | |
| dc.description.abstract | A series of symmetrical substituted formamidine-type ligands, (L1, L2 and L3) were synthesized via a solvent-free reaction, in which ethanol is produced as by-product. The ligands were characterized as to their spectroscopic and solid-state properties via FT-IR, UV-Vis and NMR spectroscopies showing a prototropic tautomerism for L2 and L3. The acetate precursor complexes Rh2(O2CR)4 where R = CH3 (C1) or CF3 (C2) were synthetized and fully characterized. Reaction of C2 with an excess of formamidine ligand yields the complexes C3, C4, C5 and C6 via a solventless reaction. The 2-fluorophenyl complex, [Rh2(di-2F-pf)4] complex, C5 was structurally characterized by single crystal X-Ray crystallography revealing a paddle-wheel type complex. Allylic oxidation reactions using the binuclear Rh complexes showed that these are active for cyclohexene conversion giving a range of products. Solvent coordination could have an effect on the catalytic behaviour of the complexes, with acetonitrile being the best solvent probably due to the solubility properties of complexes. Under these conditions, the allylic oxidation of cyclohexene produced enone as major product. The best result in terms of selectivity were obtained with C1, C4, C5 and C6 which yielded only 2-cyclohexene-1-one. | |
| dc.identifier.apacitation | Casimiro, A. (2018). <i>Synthesis and characterization of dirhodium(II) formamidinyl complexes: preliminary studies as catalyst precursors for the allylic oxidation of cyclohexene</i>. (). University of Cape Town ,Faculty of Science ,Department of Chemistry. Retrieved from http://hdl.handle.net/11427/29758 | en_ZA |
| dc.identifier.chicagocitation | Casimiro, Anna. <i>"Synthesis and characterization of dirhodium(II) formamidinyl complexes: preliminary studies as catalyst precursors for the allylic oxidation of cyclohexene."</i> ., University of Cape Town ,Faculty of Science ,Department of Chemistry, 2018. http://hdl.handle.net/11427/29758 | en_ZA |
| dc.identifier.citation | Casimiro, A. 2018. Synthesis and characterization of dirhodium(II) formamidinyl complexes: preliminary studies as catalyst precursors for the allylic oxidation of cyclohexene. University of Cape Town. | en_ZA |
| dc.identifier.ris | TY - Thesis / Dissertation AU - Casimiro, Anna AB - A series of symmetrical substituted formamidine-type ligands, (L1, L2 and L3) were synthesized via a solvent-free reaction, in which ethanol is produced as by-product. The ligands were characterized as to their spectroscopic and solid-state properties via FT-IR, UV-Vis and NMR spectroscopies showing a prototropic tautomerism for L2 and L3. The acetate precursor complexes Rh2(O2CR)4 where R = CH3 (C1) or CF3 (C2) were synthetized and fully characterized. Reaction of C2 with an excess of formamidine ligand yields the complexes C3, C4, C5 and C6 via a solventless reaction. The 2-fluorophenyl complex, [Rh2(di-2F-pf)4] complex, C5 was structurally characterized by single crystal X-Ray crystallography revealing a paddle-wheel type complex. Allylic oxidation reactions using the binuclear Rh complexes showed that these are active for cyclohexene conversion giving a range of products. Solvent coordination could have an effect on the catalytic behaviour of the complexes, with acetonitrile being the best solvent probably due to the solubility properties of complexes. Under these conditions, the allylic oxidation of cyclohexene produced enone as major product. The best result in terms of selectivity were obtained with C1, C4, C5 and C6 which yielded only 2-cyclohexene-1-one. DA - 2018 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2018 T1 - Synthesis and characterization of dirhodium(II) formamidinyl complexes: preliminary studies as catalyst precursors for the allylic oxidation of cyclohexene TI - Synthesis and characterization of dirhodium(II) formamidinyl complexes: preliminary studies as catalyst precursors for the allylic oxidation of cyclohexene UR - http://hdl.handle.net/11427/29758 ER - | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/11427/29758 | |
| dc.identifier.vancouvercitation | Casimiro A. Synthesis and characterization of dirhodium(II) formamidinyl complexes: preliminary studies as catalyst precursors for the allylic oxidation of cyclohexene. []. University of Cape Town ,Faculty of Science ,Department of Chemistry, 2018 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/29758 | en_ZA |
| dc.language.iso | eng | |
| dc.publisher.department | Department of Chemistry | |
| dc.publisher.faculty | Faculty of Science | |
| dc.publisher.institution | University of Cape Town | |
| dc.subject.other | Chemistry | |
| dc.title | Synthesis and characterization of dirhodium(II) formamidinyl complexes: preliminary studies as catalyst precursors for the allylic oxidation of cyclohexene | |
| dc.type | Master Thesis | |
| dc.type.qualificationlevel | Masters | |
| dc.type.qualificationname | MSc |