Ion-pair induced self-assembly of molecular barrels with encapsulated tetraalkylammonium cations based on a bis–trisurea stave

A bis–trisurea ligand assembles with the tetraalkylammonium halides to form the flat ‘stave’ structures or ‘barrels’ that encapsulate multiple R4N+ guests, depending on the size of the halide anion (Cl− or Br−) and the R4N+ cation.