Electrostatic models for electronically inverse hosts

Ab initio Hartree-Fock calculations have been carried out in order to get a better understanding of the formation and stability of inclusion and encap sulation complexes. The "electronically inverse" host anions known to encap sulate anionic species are formed in solution by means of a template mechan ism that tends to maximize the electrostatic potential at the place of the guest anion. A correlation is provided between the topology of the host and its Molecular Electrostatic Potential (MEP) distribution that explains fro m simple geometric considerations the differences between electronically no rmal and electronically inverse hosts, and shows that the host cage tends t o get adapted not only to the shape of the guest molecule, but also to its electrostatic potential distribution.