Research Guides

Department of Chemistry University of Oxford

Dr Kevin Lovelock

Introduction

The vast majority of chemical reactions occur in liquids. Rationalising liquid-phase reactivity is extremely difficult, as for any reaction a large number of electrons interact. Therefore, much more needs to be known about electron location and energy for reactive species in solution. In addition, solvents affect reactivity. However, our understanding of the specific and detailed effects of the solvent on reactive species is still in its infancy.

Direct measurements of liquid-phase electron location and energy (i.e. valence electronic structure) are extremely scarce, particularly for light elements, due to the problems posed by liquid vaporisation in the high vacuum conditions required for soft X-ray spectroscopy (apparatus pressure <10-8 mbar). I use synchrotron X-ray spectroscopy to measure liquid-phase electronic structure. The techniques are: X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), resonant AES (RAES), resonant X-ray emission spectroscopy (RXES), core-hole clock spectroscopy and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. I use a range of synchrotron beamlines, including at Diamond Light Source, MAX-lab (see profile picture left) and the ESRF (see picture right).

The terminology of Lewis acids and bases is an attempt to rationalise chemical reactivity. Valence electronic structure is vital for understanding and predicting the reactivity of Lewis acids (electron-pair acceptors) and Lewis bases (electron-pair donors). Lewis reactivity features across all areas of chemistry. Metal ions dissolved in ionic liquids can be used as both Lewis acidic and Lewis basic catalysts; these systems are particularly attractive due to the rare ability to fine-tune catalyst acidity/basicity.  Frustrated Lewis pairs (FLPs) have been developed as outstanding candidates for small molecule activation, including H2 (for the hydrogen energy economy) and CO2 (for carbon capture and processing).

Opportunities

Part II projects available.  Projects can focus on synchrotron- and lab-based spectroscopy, or be co-supervised to also involve a synthetic inorganic or theoretical component, thus giving you a broad introduction to this research area.  Please contact me via email or come to the Inorganic Chemistry Part II open day (9th November) for more information. 

X-Ray spectroscopy for chemistry in the 2-4 keV energy regime at the XMaS beamline: ionic liquids, Rh and Pd catalysts in gas and liquid environments, and Cl contamination in gamma-Al2O3, P. B. J. Thompson, B. N. Nguyen, R. Nicholls, R. A. Bourne, J. B. Brazier, K. R. J. Lovelock, S. D. Brown, D. Wermeille, O. Bikondoa, C. A. Lucas, T. P. A. Hase and M. A. Newton, J. Synchrotron Rad. 2015, 22 (6), 1426. DOI: 10.1107/S1600577515016148

Fine tuning the ionic liquid-vacuum outer atomic surface using ion mixtures, I. J. Villar-Garcia, S. Fearn, N. L. Ismail, A. J. S. McIntosh, K. R. J. Lovelock, Chem. Commun., 2015, 51 (25), 5367. DOI: 10.1039/C4CC06307D

The ionic liquid-vacuum outer atomic surface: a low-energy ion scattering study, I. J. Villar-Garcia, S. Fearn, G. F. De Gregorio, N. L. Ismail, F. J. V. Gschwend, A. J. S. McIntosh, K. R. J. Lovelock, Chem. Sci. 2014, 5 (11), 4404. DOI: 10.1039/C4SC00640B

Preparation and Characterisation of High-Density Ionic Liquids Incorporating Halobismuthate Anions, N. E. A. Cousens, L. J. Taylor Kearney, M. T. Clough, K. R. J. Lovelock, R. G. Palgrave, S. Perkin, Dalton Trans., 2014, 43 (28), 10910. DOI: 10.1039/C4DT00755G

Photoelectron spectroscopy of ionic liquid interfaces, K. R. J. Lovelock, I. J. Villar-Garcia, F. Maier, H.-P. Steinr├╝ck, P. Licence, Chem. Rev., 2010, 110 (9), 5158. DOI: 10.1021/cr100114t