Prof S Lotz
BSc(Hons), MSc (US), PhD (RAU)Organometallic Chemistry
E-mail: simon.lotz@up.ac.za
Telephone: 012-420-2800
 | Simon Lotz , Professor.
Lecturer, 1973-1979, RAU. Alexander von Humboldt scholarship, Würzburg, Germany 1979. Senior Lecturer RAU 1979-1982. Professor Univ. of Pretoria 1983-. Alexander von Humboldt scholarship 1986/7. Visiting professor, University of Iowa, 1996, Fellow of the Royal Society of Chemistry and member of the American Chemical Society. |
Most of our research is concerned with the synthesis, characterization and reactivity of useful organometallic com pounds. Two major goals of this research are: (1) to understand in detail the fundamental processes of ligand activation by transition metals and (2) to design and test compounds for possible application in inorganic and organic synthesis, medicinal chemistry and advanced materials.
Research activities focus on the utilization of -arene, -heterocyclic, carbyne and carbene ligands which act as binding and bridging units between transition metal fragments. Simple organic molecules are activated by their coordination to two or more metals in bimetallic or trimetallic complexes. The metal centers can act independently in a localized, or jointly in a complimentary fashion, to facilitate transformations unachievable by either metal functioning on its own. Furthermore, the activation/stabilization of simple organic molecules by transition metals often leads to the formation of novel multimetal compounds and unique reaction pathways. Recently we discovered that metal fragments exchange positions to take up preferred coordination sites on bridging ligands in heterobimetallic complexes.
Chemical reactivities and structural features of multimetal systems are compared by varying electronic and steric properties of bridging ligands and metal fragments. We have shown that metal fragments in bimetallic complexes structurally distort bridging ligands not only because of steric constraints but also by inductive and resonance electronic influences. Structure-activity correlations afford insight into new reaction pathways and are used to explain product distributions.
Selected Publications
- pi-Arene Complexes. 11. Studies on the nature and location of dimethyl amine and biscyclopenta-dienyltitaniumchloride substituents and their steric and electronic effects on the bridging arene ligand in sigma,pi-coordinated bimetallic complexes. R Meyer, PL Wessels, PH van Rooyen and S Lotz* Inorg. Chim. Acta 284 (1999) 127-132.
- A trinuclear ruthenium(II) complex with rare S,O-bridging sulfoxide ligands. SF. Lessing, S. Lotz, HM Roos and PH. van Rooyen. J. Chem. Soc., Dalton Trans. (1999) 1499-1502.
- Synthesis, characterization and crystal structures of Tc(V) and Re(V) complexes with ferrocene ligands. O Knoesen and S Lotz. In "Technesium, Rhenium and other Metals in Chemistry and Nuclear Medicine" M Nicolini and U Mazzi (eds.) SGE Editoriali, Italy (1999) 153-156.
- Ferrocenyl ligands in mixed valence high-oxidation state rhenium complexes. O Knoesen, H Görls and S Lotz* J. Organomet. Chem. 598 (2000) 108-115.
- Heteroarylphosphorus ligands in platinum(II) complexes. J Chantson, H Görls and S Lotz* Inorg. Chim. Acta. 305 (2000) 32-37.
- Thieno[3,2,-b]thiophene containing carbene complexes of chromium and tungsten. M Landman, H Görls and S Lotz* Eur. J. Inorg. Chem. (2000) in press.
- Solid and solution structures of the novel diferrocenyl ligand and oxorhenium complex. O Knoesen, PL Wessels, H Görls and S Lotz* Inorg. Chem. (2001) 40(6), pp1199-1205.
- Synthesis and crystal structures of carbene complexes with conjugated thiophene units. M Landman, H Görls and S Lotz* J. Organomet. Chem. (2001) 617-618, pp280-287.
- Chromium and tungsten carbene complexes of thieno[3,2-b]thiophene. Landman, M., Görls, H., Lotz, S, European Journal of Inorganic Chemistry (2001), pp233-238.
- Metal-metal bond cleavage of carbene complexes by halogens: The crystal and molecular structures of ax-[Mn2(CO)9{C(OEt)2-thienyl}], [Mn(CO)4(I)-{C(OEt)2-thienyl}] and eq-[Mn2(CO)9{C(NH2)2-thienyl}]. Simon Lotz, Marilé Landman, Daniela I. Bezuidenhout, Andrew J. Oliver, David C. Liles and Petrus H. van Rooyen, J. Organometal. Chem., 690, (2005), 5929-5937.
- μ-Furan-2,5-diylbis(methoxycarbene)-bis[pentacarbonylchromium(0)]. David C. Liles and Simon Lotz, Acta Cryst. (2006), E62, m331-m334. [Reprint (pdf format)].
- Mary S. Thomas, David C. Liles, Marilé Landman, Elizabeth M. van der Merwe and Simon Lotz, "The synthesis, structural features and thermal behaviour of thiophene-containing dithiocarboxylate complexes of zinc(II)." Polyhedron, 25, 3562-3568, (2006).
- Daniela I. Bezuidenhout, David C. Liles, Petrus H. van Rooyen and Simon Lotz, "Axial and equatorial carbene ligands of dimanganese and dirhenium monocarbene complexes: Synthesis, characterisation and structural studies." J. Organometal. Chem., 692, 774-783, (2007).
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