1. Department of Chemistry, University of York, Heslington, York YO10 5DD, U.K.
2. Department of Chemistry, Chemistry Research Laboratories, University of Oxford, Oxford OX1 3TA, U.K.
3. Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS. U.K.
4. UK National Crystallography Service, University of Southampton, Highfield, Southampton SO17 1BJ, U.K.
5. Diamond Light Source Ltd., Diamond House,
Harwell Science and Innovation Campus, Didcot OX11 0DE, U.K.