1. Department of Chemistry, University of York, Heslington YO10 5DD, York, U.K.
2. Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, U.K.
3. Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, U.K.
4. Diamond Light Source Ltd, Didcot OX11 0DE, U.K.
5. Department of Chemistry, University of Southampton, Southampton SO17 1BJ, U.K.