Full Text Available
Note: Clicking the button above will open the full text document at the original institutional repository in a new window.
α-Diimine complexes of transition metals for the polymerisation of lower α-olefins
Thesis (MSc (Chemistry and Polymer Science))--University of Stellenbosch, 2005.
Saved in:
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Thesis |
| Language: | English |
| Published: |
Stellenbosch : University of Stellenbosch
2008
|
| Subjects: | |
| Tags: |
No Tags, Be the first to tag this record!
|
| _version_ | 1867614087127498752 |
|---|---|
| access_status_str | Open Access |
| author | Fullaway, Phillip V. |
| author2 | Raubenheimer, H. G. |
| author_browse | Fullaway, Phillip V. Raubenheimer, H. G. |
| author_facet | Raubenheimer, H. G. Fullaway, Phillip V. |
| author_sort | Fullaway, Phillip V. |
| collection | Thesis |
| dc_rights_str_mv | University of Stellenbosch |
| description | Thesis (MSc (Chemistry and Polymer Science))--University of Stellenbosch, 2005. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/2341 |
| institution | Stellenbosch University (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:46:27.621Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2008 |
| publishDateRange | 2008 |
| publishDateSort | 2008 |
| publisher | Stellenbosch : University of Stellenbosch |
| publisherStr | Stellenbosch : University of Stellenbosch |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/2341 α-Diimine complexes of transition metals for the polymerisation of lower α-olefins a-Diimine complexes of transition metals for the polymerisation of lower a-olefins Fullaway, Phillip V. Raubenheimer, H. G. Grumel, V. University of Stellenbosch. Faculty of Science. Dept. of Chemistry and Polymer Science. Dissertations -- Chemistry Theses -- Chemistry Complex compounds Transition metal complexes Polymerization Alkenes Thesis (MSc (Chemistry and Polymer Science))--University of Stellenbosch, 2005. In this study several potential polymerisation catalysts were synthesised. This was accomplished by coordinating α-diimine ligands such as N,N'-diferrocenyldiazabutadiene (DFDAB), N,N'-dimesityldiazabutadiene (DMDAB) as well as the bidentate amine N,N,N',N'-tetramethylethylenediamine (TMEDA), to several transition metals. The multi-step synthesis of N,N'-diferrocenyldiazabutadiene (DFDAB) from ferrocene involved the use of lithiated ferrocene, iodoferrocene, N-ferrocenylphthalimide and aminoferrocene; the latter three were characterised. This ligand was coordinated to the transition metal ions iron(II) and zinc(II) to form Fe(DFDAB)Cl2 and Zn(DFDAB)Cl2 respectively. 1H and 13C NMR, FT-IR and mass spectrometry revealed that the expected product had been synthesised in a useful form. 2,4,6-Trimethylaniline reacted with glyoxal to form N,N'-dimesityldiazabutadiene (DMDAB). The DMDAB ligand was coordinated to the transition metal ions zinc(II) and silver(I) to form Zn(DMDAB)Cl2 and Ag(DMDAB)2 respectively. Characterisation now also include molecular and crystallographic structural determinations by means of X-ray diffractometry. Another N-donor complex, Cr(CO)4(TMEDA), was also prepared by coordinating N,N,N',N'-tetramethyl ethylenediamine (TMEDA) to Cr(CO)5(THF). This was done to give an indication of the activity of low oxidation state complexes in the catalysis of olefin polymerisation. The metal-α-diimine complexes mentioned above were employed in the polymerisation of the monomers ethylene and 1-pentene probably according to a cationic mechanism. High density, high molar mass polyethylene products with narrow polydispersities were obtained. The chromium(TMEDA) complex produced polyethylene exhibiting ultra-high molar mass (> 10 000 kg/mol). The polymerisation of 1-pentene, using the Fe(DFDAB)Cl2 complex, afforded oligo-pentene with a molar mass of ~800 g/mol. After an unsuccessful attempt to prepare the (CO)5Cr=C(OZrCp2Cl)(ferrocenyl) modified Fischer-type carbene complex, the (CO)5Cr=C(OMe)(ferrocene) complex was eventually insolated. Elucidation of its molecular structure was accomplished by X-ray diffractometry. Finally, the DFDAB-ligand was coordinated to Fe2(CO)9 to generate Fe(CO)3(DFDAB) in another attempt to investigate the role of carbonyl groups and also low oxidation state metals in polymerisation reactions [compare to Cr(CO)4(TMEDA) unit above]. The sensitivity of this complex towards moisture and air prevented such action. 2008-07-09T12:12:09Z 2010-06-01T08:46:29Z 2008-07-09T12:12:09Z 2010-06-01T08:46:29Z 2005-12 Thesis http://hdl.handle.net/10019.1/2341 en University of Stellenbosch application/pdf Stellenbosch : University of Stellenbosch |
| spellingShingle | Dissertations -- Chemistry Theses -- Chemistry Complex compounds Transition metal complexes Polymerization Alkenes Fullaway, Phillip V. α-Diimine complexes of transition metals for the polymerisation of lower α-olefins |
| title | α-Diimine complexes of transition metals for the polymerisation of lower α-olefins |
| title_full | α-Diimine complexes of transition metals for the polymerisation of lower α-olefins |
| title_fullStr | α-Diimine complexes of transition metals for the polymerisation of lower α-olefins |
| title_full_unstemmed | α-Diimine complexes of transition metals for the polymerisation of lower α-olefins |
| title_short | α-Diimine complexes of transition metals for the polymerisation of lower α-olefins |
| title_sort | α diimine complexes of transition metals for the polymerisation of lower α olefins |
| topic | Dissertations -- Chemistry Theses -- Chemistry Complex compounds Transition metal complexes Polymerization Alkenes |
| url | http://hdl.handle.net/10019.1/2341 |
| work_keys_str_mv | AT fullawayphillipv adiiminecomplexesoftransitionmetalsforthepolymerisationofloweraolefins |