Specific Encapsulation of Acetylcholine Chloride by a Self-Assembled Molecular Capsule with Sulfonamido Moiety

New molecular capsule 12, which encapsulates only acetylcholine chloride in the ion-pair form, has been developed. Cavitand 1 with four sulfonamido moieties on the upper rim of tetraimino-cavitand self-assembled to form a stable molecular capsule in the presence of an acetylcholine chloride guest through eight intermolecular —NH···O═S hydrogen bonds, two from each of the four paired sulfonamide units.