Conradie, JeanetStuurman, Nomampondomise Flaurette2018-01-222018-01-222007http://hdl.handle.net/11660/7662Dissertation (M.Sc.(Chemistry))--University of the Free State, 2007Rhodium compounds are one of the most widely used industrial homogeneous catalysts for organic raw material processing. Classic examples of efficacious catalyst systems are: methanol carbonylation to give acetic acid in the presence of [Rh(C0)₂I₂] complex (Monsanto prosess),¹ alkene hydroformylation on RhHCO(PPh₃)₂ catalyst, hydrogenation of olefins and acetylenes with the help of RhCl(PPh₃)₃ (Wilkinson's catalyst)² and the use of [Rh(acac)(CO)i]₂ in the hydroformylation of olefins³ (Figure 1.1). In the field of olefin polymerization, metal complexes with a coordinatively unsaturated Lewis acid metal centre are generally required, whereas for transformations such as the carbonylation of methanol, electron-rich metal centres are necessary to favour oxidative addition of Mel to Rh(I).⁴ ⁵ The high catalytic reactivity of these rhodium complexes is in many respects due to the nature of ligand surroundings.⁶ Supported rhodium carbonyl complexes form an important class of catalysts and precursors for the preparation of different supported rhodium species.⁷ The reactivity of rhodium(I) dicarbonyl complexes, and in particular, the rate of carbonyl ligand substitution, is defined by the electron state of the rhodium centre.⁶ The latter ultimately depends on donor-acceptor characteristics of chelated ligand atoms coordinated directly with the metallic centre.⁶ Kinetic and thermodynamic studies on the octahedral rhodium(III) complexes has gained momentum. This field has also given rise to the important discovery of the photosensitivity of rhodium complexes. β-diketone complexes of Rh(I) of the type [Rh(β-diketone)(D)₂ (where D are electron donors such as CO, ethylene and dienes) undergo substitution reactions with a large variety of ligands. To examine these reactions, knowledge of the relative 𝘵𝘳𝘢𝘯𝘴-effect of these ligands is necessary. The unexpected discovery of the antitumor activity of cisplatin has opened up the 'era of inorganic cytostatics' .⁹ In the search for new organometallic compounds or inorganic coordination complexes with antitumor properties, it was found that some rhodium(!) complexes, for example [Rh(acac)(cod)] (acetylacetonate- I ,5-cyclooctadienerhodium(I)), showed antineoplastic activity comparable to, or even better than that of 𝘤𝘪𝘴𝘱𝘭𝘢𝘵𝘪𝘯. ¹º ¹¹enβ-diketoneRhodium(I)Oxidative additionpKₐ'Group electronegativityCrystallographyRhodium compounds -- SynthesisDissertationUniversity of the Free State