The use of transition metals in the fields of catalysis and medicine is a fast-growing area of interest. South Africa has access to a range of transition metals, especially the Platinum group metals, essential to both catalysis and medicine. The current projects involve the design and synthesis of organometallic and coordination compounds with applications as catalysts, medicines and as new materials. These projects are interdisciplinary, addressing problems at the interface of organic, inorganic, organometallic and polymer chemistry. Described below is a compilation of research topics that are being investigated.


Metal Complexes of Thiosemicarbazones:  Thiosemicarbazones have established pharmacological activities as anti-tumor and anti-malarial agents. Coordination to a metal is known to increase the biological activity, as well as decrease side effects.





A series of monomeric and dimeric aryl thiosemicarbazones have been prepared and their corresponding palladium complexes have also been synthesized and characterized. The
thiosemicarbazone ligands show anticancer activity, and the palladium complexes are being screened for anticancer and antimalarial activity.


Metallodendrimers:  There is prolific interest in well-defined, three-dimensional, tree-like polymers better known as dendrimers (Greek: dendron = tree). Transition metals may be incorporated either in the core, on the periphery or interspersed in the dendritic network, giving rise to multinuclear complexes known as metallodendrimers. The use of metallodendrimers in catalysis and as biological agents has been cited extensively. This has largely been due to the observation that in quite a few cases multinuclear dendrimers have shown enhanced performance when compared to mononuclear complexes.

A key area of research focuses on the synthesis of various metal-containing dendrimers (Pd, Ni, Rh, Ru) based on a poly(propyleneimine) dendritic scaffold. These have been used as ethylene oligomerisation/polymerization, Heck cross-coupling, hydrformyaltion catalyst precursors and as biological (anticancer) agents.


Metal-containing polymers:  Metal-containing polymers with well-defined and controlled architectures are of growing interest due to their interesting physical properties and ability to self- assembly to yield functional supramolecular materials. This project seeks to address the synthesis of polynuclear catalysts that maintain high activity and selectivity and can be easily separated from reaction mixtures. The immobilization of transition metal catalysts on polymeric offers a number of advantages. The supported complexes can be readily separated from reaction mixtures, facilitating recycling of the catalysts to avoid environmental toxicity and makes purification of products easier. This area bridges the gap between homogeneous and heterogeneous catalysis. The rationale for this study is to synthesize alternative, cheaper, more efficient catalysts that will be of interest to the South African industry and international markets.