Supramolecular complexes with macrocycles: Surprises and insights

Abstract

Progress in fundamental science lives on falsification of existing theories or hypotheses.[1] This is a major reason why we need experiments, and why we must not only be prepared for surprises, but should actually seek for those. Chemists all too often find satisfaction only if their results confirm their anticipation. Progress in supramolecular chemistry as a relatively new field of science especially relies on conclusions from unexpected results. Although there are many reviews and already several monographs in the field,[2] authors and even more students understandably prefer rules and orders, and dislike complications. This could lead to the impression that as e.g. in classical mechanics only the intelligent application of recognized laws is what will in future count in our field. However, even if one only would be interested in making e.g. perfect new receptor molecules a better understanding of the relevant interaction mechanisms will be of significant help in a rational approach to such goals. Synthetic supramolecular chemistry is particularly suited for experiments which challenge existing hypotheses, as entirely new experimental systems such as new hostguest complexes can be designed in order to answer specific questions. In the present chapter an attempt is made to illustrate results in macrocyclic chemistry, which at least at first sight are unexpected, but can lead to new insights in theory. Most of the illustrations will be taken from work of the author's laboratory; these and the selected other examples are meant to be an incentive for both experimentalists and theoreticians for the future development of one of the most promising fields in chemistry. © 2005 Springer. Printed in the Netherlands.