Dr Damien Murphy Project Titles
1. Pressure effects in homogeneous catalysis; investigation of spin dynamics via pulsed EPR
In many homogeneous reactions, particularly for alkene oligomerisation/polymerisation, high pressures are often utilised to achieve higher rates and optimised reaction performance. Under these extreme conditions, the nature of the transition states or reaction intermediates is often poorly defined. However understanding the structure of these states under such conditions is vitally important, particularly when variable redox states are involved in the reaction. In such cases, control of the electron spin states and the oxidation state, is vitally important. As pressure can influence the structure of the intermediates, the spin orbit coupling can also be indirectly perturbed, thus facilitating the formation of one spin state over another. One ideal way to probe not only the structure of such intermediates but also their spin states under pressure, is to utilise a range of advanced electron paramagnetic resonance (EPR) techniques. Therefore in this project, a range of different classes of Cr based complexes, utilising the bis-phosphine family of ancillary ligands to stabilise the active Cr centres, will be studied under reaction conditions at elevated pressures. The mechanistic details of the reaction intermediates will thus be probe, in order to better understand the role of spin transitions in the reaction pathways.