1. a Centre for Molecular Materials and Department of Chemistry , The University , Sheffield , S3 7HF , England
2. b Sir Edward Frankland Fellow of the Royal Society of Chemistry 1994/95
3. c Department of Chemistry , University of Southampton , Southampton , SO17 1BJ , England
4. d Unilever Research, Port Sunlight Laboratory , Quarry Road East, Bebington, Wirral , L63 3JW , England