Kyungsoo Paek

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.

A new chromogenic, self-assembled molecular capsule G@2₂is developed by introducing four (N,N-dimethyl-4-aminophenyl) azobenzyl moieties on the upper rim of a resorcin[4]arene-based amidoimino-cavitand. The tuning of conjugation between amido and (N,N-dimethyl-4-aminophenyl)azobenzyl groups by acid–base titration allows naked-eye observation of molecular capsule formation.

The facile synthesis of a resorcin[4]arene-based imino-cavitand with benzamido moieties and its self-assembly into molecular capsules are reported. Benzamido-iminocavitand 2 efficiently self-assembled into thermally inert molecular capsules in the presence of suitable guests via the eight intermolecular N–H⋯OC hydrogen bonds.

Resorcin[4]arene-based tetrakis(N-hydantoinylamido)cavitand 1 forms a stable molecular capsule in the presence of suitable anionic guests such as CH(3)OSO(3)(-) or BF(4)(-) in C(2)D(2)Cl(4). Molecular capsule G(2)@1(2) is stabilized by the eight intermolecular imide N-H···O═C hydrogen bondings, two from each four paired hydantoinyl units, and the eight intramolecular amide N-H···O-CH(2)-O hydrogen bondings, four on each two cavitands. The formations of molecular capsules were confirmed by (1)H, 2D NOESY, and 2D-DOSY NMR.