Catalytic applications of transition metal-main group metal heterobimetallic complexes

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The project builds upon recent work in the Whittlesey group that has led to the formation of new heterobimetallic complexes which feature unsupported bonds between a transition metal (TM) and a main group metal M', specifically zinc. Heterobimetallic complexes that combine an electron-rich late transition metal centre with an electron-deficient M' partner have the potential to confer two very different (potentially complementary) activities in catalytic reactions. Catalytically active TM-M' systems in the literature mainly feature the electron-deficient M' centre embedded in a ligand scaffold. However, this reduces the level of coordinative unsaturation at both TM and M' and makes it essentially impossible to differentiate these complementary effects from being (i) the action of both the TM and M' in directly activating a substrate or (ii) M' acting indirectly to tune the properties of the TM centre. Our systems therefore offer a new approach to this area of chemical research, as the coordinative unsaturation of the Ru and Zn centres results in remarkable stoichiometric and catalytic reactivity. We will now explore the full potential of these unsupported TM-M' heterobimetallic complexes in the stoichiometric and catalytic activation of small molecules. We will aim to establish the limits of the TM/M' combination, as this is vital for showing the viability of our unsupported bond methodology in a broader sense. This will involve variation of (i) both M' and the substituents on it, (ii) the supporting ligands on TM (e.g. N-heterocyclic carbenes (NHCs) and phosphines (PR3)), (iii) the TM precursor (e.g. change of LnRu to [Pt(NHC)2H]+, [Ir(NHC)2H2]+). The experimental work will be supported by calculations in collaboration with Professor Stuart Macgregor at Heriot-Watt University, with whom Whittlesey has a current joint EPSRC grant. The project is ideal in nature for a PhD student to develop skills in the manipulation of air-sensitive materials, learn the principles of catalysis and gain exposure to modern spectroscopic and characterisation techniques (NMR spectroscopy, X-ray crystallography). Moreover, the target area to develop novel chemistry of heterobimetallic systems is a topic of worldwide research interest. Thus, the student will receive exposure to leading researchers in model inorganic/organometallic chemistry. The potential applications of this research are in the design of novel homogeneous catalysts, whose novelty lies in improved activity or transformations of a type inaccessible to either TM or M' alone. Achievement of either of these aims would define the benefit of this research and it's relevance to EPSRC goals of catalysis and sustainability. The second supervisor, Mike Hill, has expertise in s- and p-block chemistry and therefore will be able to assist in achieving appropriate choices of M'.