Multiple hydrogen-bonding interactions are widely used for the design of hollow self-assembled structures capable of molecular encapsulation. In particular, intermolecular hydrogen bonds between urea functions are responsible for the stability of dimeric calixarene capsules, while the slow exchange of guests in self-folded caviplexes is caused by a seam of intramolecular hydogen bonds between amide groups. [3] Herein we describe a novel type of self-assembled concave structures 1 4 ´4 X À in which the shallow socket of a resorcarene is extended by a cyclic hydrogen-bonded array of four halide ions and four ammonium ions attached to the wide rim of the macrocycle. We demonstrate also that 1 4 ´4 Cl À , but not 1 4 ´4Br À , is able to complex certain alcohols in CDCl 3 through the formation of hydrogen bonds and inclusion into the p-basic resorcarene cavity.
Condensation of resorcarenes [4] with primary amines and formaldehyde readily gives the corresponding tetrabenzoxazine derivatives. The subsequent cleavage of the benzoxazine rings with HCl or HBr (n-butanol, 80 8C) yields the tetraammonium salts 1 4 ´4 X À (X À Cl À , [6] Br À ) in 80 ± 90 % yield.