The chemical character of complexes between organic hosts and guests will be studied. The research will focus on the incarceration of guests in rigidly hollow hosts either without holes (carcerands) or with holes (hemicarcerands) in their shells. The free energies of constrictive binding by hemicarceplexes will be measured for both aliphatic and aromatic guests in the molecular weight range of about 80-120. The rates of complexation and decomplexation will be correlated with the relative sizes of the guests and portals in hemicarceplexes. Comparisons will be made between the rates and products of reactions run in the interior phases of dissolved demicarceplexes, and those run in the same solvents free of the hosts. Guests will be designed, prepared, and studied, only a part of which can be incarcerated, the rest being too large to pass through the portals of the hosts. A small molecular tether will connect the two parts. Other guests will be studied, one part of which will be contained in one hemicarcerand and a second part in a second hemicarcerand. The product will be two hemicarceplexes connected by a short molecular tether. New families of carcerands and hemicarcerands will be designed and synthesized. The Organic Synthesis Program is funding the renewal of this Nobel Prize research. It will continue its development of the chemistry of small molecules imprisoned inside larger molecules. The work has the potential to lead to very unique new patterns of reactivity.
