1. Contribution from the Christopher Ingold Laboratory, Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, U.K., Strathclyde Institute of Pharmacy and Biomedical Sciences, 27 Taylor Street, University of Strathclyde, Glasgow G4 0NR, U.K., ISIS facility, CCLRC Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 1QX, U.K., Molecular Materials Centre, School of Chemical Engineering and Analytical Sciences, University of Manchester, Sackville Street, Manchester M60 1QD...