1. School of Chemical Engineering and Analytical Science, The University of Manchester, Oxford Road, Manchester, M13 9PL, U.K., Department of Analytical Sciences, Sanofi-Aventis Research, Willowburn Avenue, Alnwick, Northumberland, NE66 2JH, U.K., and School of Chemistry, The University of Manchester, Brunswick Street, Manchester, M13 9PL, U.K.