Resorcarenes in the boat conformation as building blocks for hydrogen-bonded assemblies including two ammonium cations

Crystal structures are reported for various co-crystals of rccc-resorcarene s with triethylammonium chloride. Usually, two molecules of a C(2x-)symmetr ic tetraester 2 in the boat conformation are linked through four hydrogen-b onded chloride anions to give dimeric assemblies. Two of the chloride anion s may be replaced by four hydrogen-bonded ethanol molecules in an otherwise similar structure. These assemblies, which consist of six or eight compone nts, posses voluminous, negatively charged chambers in which two triethylam mionium cations, 3-. are included as guests by strong electrostatic and hyd rogen-bonding interactions, The host-guest N-H . . . Cl hydrogen bonds were clearly detected at 173 K. These are the first examples of hydrogen-bonded , solid-stale capsules trapping two ions of the same charge in close proxim ity. In the 1:2 complex with 3(-)Cl(-), the molecule of the parent resorcar ene 1 also adopts a boat conformation whose cavity is considerably extended by four hydrogen-bonded chloride anions. The pocket formed in this way aga in includes two 3(-) ions as a result of electrostatic and hydrogen bonding host-guest interactions. All these structures show that the boat conformer s of resorcarenes can be used as a novel motif for the construction of hydr ogen-bonded assemblies capable of molecular inclusion and encapsulation.