Binding Modes of Nonspherical Anions to N-Alkylammonium Resorcinarenes in the Solid State

Hydrogen bonded stabilized N-alkylammonium resorcinarene cavitands were synthesized with nonspherical nitrate, triflate, and picrate anions. Together with electrostatic interactions, the binding of the anions with several hydrogen bond donor sites proceeds through a complex array of intra- and intermolecular hydrogen bonds, responsible for the cavitands-like structures of these compounds. These N-alkyl ammonium resorcinarenes bind the larger nonspherical anions into twisted cavitand-like structures transforming the resorcinarene conformation from near symmetrical to extremely distorted.