1. Sasol Technology (UK) Ltd, Purdie Building, North Haugh, St. Andrews, KY16 9ST, U.K., Sasol Technology (Pty) Ltd, R&D Division, 1 Klasie Havenga Road, Sasolburg, 1947, South Africa, and School of Chemistry, University of St. Andrews, Purdie Building, St. Andrews, KY16 9ST, U.K.