J.L Atwood – författare

There is no doubt that the field of artificial membrane transport using synthetic ionophores has advanced remarkably in the past 15 years due primarily to the synthesis of new ionophores. Even though the theoretical framework substantially predated this activity, the merging of theory with transport experiment has often been sketchy. The purpose of this outline has been to examine key examples to illustrate the underlying principles and to suggest how experimental variables dominate the results obtained. To a very good approximation the assumption of a "diffusion" regime is often justified, is easily confirmed experimentally and provides a clear framework for exploitation of the inherent selectivity of a given ionophore. Thus for synthetic chemists who wish a "quick and nasty" experiment to examine the question of selectivity, the recipe is clear: a mixture containing all ions of interest in a standard experiment for each ligand of interest using a moderately stirred (100-200 rpm) cell and analysis of the mixture produced on the OUT side of the cell at a fixed, small extent of transport. Together with duplicates and controls, this modest set of experiments will place the results on an unambiguous footing from which clear conclusions about each ionophore's characteristics are readily obtained. For those with more detailed interests in the transport process the demands are correspondingly higher.

The Supramolecular Compounds refer to organised multi-molecular assemblies and associated phenomena. The stability and the properties of these compounds strongly involve structural three-dimensional (3D) information. The crystal itself can be considered as a giant supermolecule. Thus, a thorough understanding of crystal structures and crystal growth provides a unique information on the intermolecular interactions. Indeed, each crystal reflects in a particular way the recognition properties of molecules. More so, modern crystallography allows to study in detail two- or three-component crystalline solids in which the recognition processes can be seen from the structural standpoint. Crystallography of smaller and smaller single crystals, faster and faster experiments, time-resolved x-ray crystallography, are extremely potent source of physico-chemical information. The present Advanced Study Institute (A.S.I.) - which was planned five years ago as the 22nd Course of the International School of Crystallography (director: T. L. BLUNDELL), 1-11 June 1995, E.Majorana Centre, Erice, Italy - is probably the first international meeting specifically devoted to the Crystallography of Supramolecular Compounds. The presence of crystallographers, chemists and physicists enhanced the coherence of the typical sequence: Conception and Design - Synthesis - Structure and Visualisation - Properties. The interactive and interdisciplinary character of this research is central to the development of general structural models for a large spectrum of compounds: ionophores, cryptates, fullerenes, calixarenes, cyclodextrins, cyclotriveratrylenes, pillar type compounds, zeolites, hydrates, solvates and others.

There is no doubt that the field of artificial membrane transport using synthetic ionophores has advanced remarkably in the past 15 years due primarily to the synthesis of new ionophores. Even though the theoretical framework substantially predated this activity, the merging of theory with transport experiment has often been sketchy. The purpose of this outline has been to examine key examples to illustrate the underlying principles and to suggest how experimental variables dominate the results obtained. To a very good approximation the assumption of a "diffusion" regime is often justified, is easily confirmed experimentally and provides a clear framework for exploitation of the inherent selectivity of a given ionophore. Thus for synthetic chemists who wish a "quick and nasty" experiment to examine the question of selectivity, the recipe is clear: a mixture containing all ions of interest in a standard experiment for each ligand of interest using a moderately stirred (100-200 rpm) cell and analysis of the mixture produced on the OUT side of the cell at a fixed, small extent of transport. Together with duplicates and controls, this modest set of experiments will place the results on an unambiguous footing from which clear conclusions about each ionophore's characteristics are readily obtained. For those with more detailed interests in the transport process the demands are correspondingly higher.

The Supramolecular Compounds refer to organised multi-molecular assemblies and associated phenomena. The stability and the properties of these compounds strongly involve structural three-dimensional (3D) information. The crystal itself can be considered as a giant supermolecule. Thus, a thorough understanding of crystal structures and crystal growth provides a unique information on the intermolecular interactions. Indeed, each crystal reflects in a particular way the recognition properties of molecules. More so, modern crystallography allows to study in detail two- or three-component crystalline solids in which the recognition processes can be seen from the structural standpoint. Crystallography of smaller and smaller single crystals, faster and faster experiments, time-resolved x-ray crystallography, are extremely potent source of physico-chemical information. The present Advanced Study Institute (A.S.I.) - which was planned five years ago as the 22nd Course of the International School of Crystallography (director: T. L. BLUNDELL), 1-11 June 1995, E.Majorana Centre, Erice, Italy - is probably the first international meeting specifically devoted to the Crystallography of Supramolecular Compounds. The presence of crystallographers, chemists and physicists enhanced the coherence of the typical sequence: Conception and Design - Synthesis - Structure and Visualisation - Properties. The interactive and interdisciplinary character of this research is central to the development of general structural models for a large spectrum of compounds: ionophores, cryptates, fullerenes, calixarenes, cyclodextrins, cyclotriveratrylenes, pillar type compounds, zeolites, hydrates, solvates and others.

The contents of this volume originate from the joint Inclusion Phenomenal Cyclodextrins Symposium held at Lancaster in July 1986. Consisting of 50 extended ab­ stracts and 21 original contributions, the reader will find an up-to-date survey of the current state of research into, and applications of, inclusion compounds. Topics covered range from cyclodextrin complexes and their use as media for selective chemical reagents and their applications in chromatography and in the pharmaceutical and agricultural areas; the synthesis of new hosts, particularly those containing hydrophobic cavities; the characterisation of inclusion compounds using crystallographic and spectroscopic techniques; the use of inclusion com­ pounds as enzyme models; macrocyclic complexes and ionophores; to intercalates and zeolites. The Symposium was extremely successful, being attended by some 250 delegates drawn from 23 nations. It is hoped that the reader will recapture the flavour of the meeting from reading this volume. xi Journal of Inclusion Phenomena 5 (1987), 1-2. 1 © 1987 by D. Reidel Publishing Company. Preface The joint meeting comprlslng the 4th International Symposium on Inclusion Phenomena and the 3rd International Symposium on Cyclodextrins was held on 20 - 25 July, 1986 at the University of Lancaster, Great Britain, and followed on from the previous joint meeting held in Tokyo in July, 1984. The meeting was sponsored by the Royal Society of Chemistry.