Structure?reactivity relations of inclusion compoundsThis article is based (partly) on a presentation which will be made at the European Research Conference (EURESCO) on "Molecular Crystal Engineering - EuroConference on Design and Preparation of Molecular Materials" (Acquafredda di Maratea, Italy, 31 May - 5 June 2003) organised by the European Science Foundation and supported by the European Commission, Research DG, Human Potential Programme, High-Level Scientific Conferences, Contract HPCF-CT-2002-00270. This information is the sole responsibility of the author(s) and does not reflect the ESF or Community's opinion. The ESF and the Community are not responsible for any use that might be made of data appearing in this publication.