ABSTRACT
A number of terms are used in the literature to describe these supermolecules: host-guest compound, inclusion compound, clathrate, molecular complex, intercalate, carcerand, cavitand, crow, cryptand, podand, spherand, and so on. Many detailed schemes have been proposed for the classi cation of these substances according to the nomenclature given above. us, the term “clathrate,” which is derived from the Latin word clathratus meaning “enclosed by bars of a grating,” was used to describe a three-dimensional host lattice with cavities for accommodating guest species. e term Einschlussverbindung (inclusion compounds), introduced by Schlek in 1950, seems to be the most suitable for all inclusion-type systems considering some characteristic features of the host-guest association, such as no-covalent bond between the host and guest and/or the dissociation-association equilibrium in solution (Cramer 1954).
