Multiple Transformations among Anion-based AL Assemblies: Bicapped Trigonal Antiprism AL, Tetrahedron AL, and Triple Helicate AL (A = Anion).

The construction of sophisticated, high-nuclearity polyhedral cages is an attractive yet challenging task in supramolecular chemistry. Herein we report the anion-coordination-driven assembly (ACDA) of a series of AL architectures ("A" denotes anion, L is ligand, = 1, 2, 4) with a biphenylene-spaced -(urea) ligand including triple helicate AL (), tetrahedron AL (), and the octanuclear, bicapped trigonal antiprism (or parallelepiped) AL (). Among them, is held by 96 hydrogen bonds, the largest number ever reported in a discrete polyhedron, and encapsulates multiple guests (three tetramethylammonium cations) in three compartments. Remarkably, multiple reversible transformations of these dynamic assemblies have been realized by alternation of the template guest, solvent, and concentration. Furthermore, a chiral ligand () with carbon stereocenters at both termini of the -(urea) backbone was designed and assembled with phosphate to form the enantio-pure triple helicate or tetrahedron. The chiral amplification effect in the tetrahedral complex is significantly larger than that in the triple helicate as a function of the point chirality.