M.Sc. / This study deals with the synthesis of nitrogen-donor imidazolyl- and pyrazolyl-salicylaldimine compounds, their reactions with selected transition metals and applications as catalysts for Heck coupling reactions of aryl halides with butyl acrylate, ethylene polymerization reactions and reactions of higher α-olefins. Imidazole-based salicylaldimine compounds 2,4-di-tert-butyl-6-{[2-(1H-imidazol-4-yl)-ethylimino]-methyl}-phenol (L1) and 4-tert-butyl-2-{[2-(1H-imidazole-4-yl)-ethylimino]-methly}-phenol (L2) were prepared by Schiff base condensation reaction of histamine dihydrochloride with 3,5-di-tert-butyl-2-hydroxybenzaldehyde and 5-tert-butyl-2-hydroxybenzaldehyde respectively. The compounds were characterized by 1H, 13C{1H} NMR and IR spectroscopy; and high resolution mass spectrometry (HRMS). Compounds 2-{[2-(1H-imidazole-4-yl)-ethylimino]-methly}-phenol (L3), 2,4-di-tert-butyl-6-{[2-(3,5-dimethyl-pyrazol-1-yl)-ethylimino]-methyl}-phenol (L4), 2,4-di-tert-butyl-6-[(2-pyrazol-1-yl-ethylimino)-methyl]-phenol (L5) and 2,4-di-tert-butyl-6-{[2-(3,5-diphenyl-pyrazol-1-yl)-ethylimino]-methyl}-phenol (L6) were synthesized according to literature procedure. Reactions of L1-L3 with [PdCl2(MeCN)2] yielded complexes 2.1-2.3 respectively. Ligand L1 was also complexed with [FeCl2] and [CoCl2] to give complexes 2.4 and 2.5 respectively, while complexes 2.6-2.15 were synthesized by reactions of L1, L2 and L4-L6 with [VCl3] and [CrCl3(THF)3]; all in a ratio of 1:1. The palladium(II) complexes (2.1-2.3) were characterized by 1H, 13C{1H} NMR and IR spectroscopy, mass spectrometry and elemental analysis, while complexes 2.4-2.15 were characterized by IR spectroscopy, mass spectrometry and elemental analysis due to their paramagnetic nature. The structures of complexes 2.1 and 2.4 were confirmed by single crystal X-ray diffraction analysis. All the complexes formed were mononuclear.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:uj/uj:7064 |
| Date | 16 May 2011 |
| Creators | Yankey, Margaret |
| Source Sets | South African National ETD Portal |
| Detected Language | English |
| Type | Thesis |
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