The inner phase of molecular container compounds as a novel reaction environment

The conceptual idea of molecular container compounds and their synthesis ha s opened an entirely new and very interesting research field: the chemistry of and within molecular container compounds and their complexes. Molecular containers have inner phases just large enough to accommodate a single gue st molecule. Beginning with Donald J. Cram's first synthesis of a carcerand , which permanently entrapped a single guest molecule, many other container s such as hemicarcerands, molecular lantern, self-assembled capsules and fu llerenes have been synthesized and studied. Not only is the design and deve lopment of new container compounds an ongoing challenge for organic chemist s, but also the systematic investigation of chemical reactions within their inner phases. The results of a large variety of inner phase reactions span ning acid-base, reduction, oxidation, nucleophilic substitution, addition, thermal, photochemical and pericyclic reactions have provided us with more insight into the relationship between bulk phase and inner phase reactants and the mechanism of the transfer of electrons and photons through the insu lating shell of a container molecule. They have also led to very spectacula r applications of molecular container compounds such as the stabilization o f reactive intermediates by incarceration. These highlights of inner phase chemistry and the current efforts and successes towards using molecular con tainers as catalytic reaction vessels are presented and discussed.