Homochiral supramolecular M2L4 cages by high-fidelity self-sorting of chiral ligands.

A 1,1'-binaphthyl-based bis(pyridine) ligand (1) was prepared in racemic and enantiomerically pure form to study the formation of [Pd2(1)4] complexes upon coordination to palladium(II) ions with regard to the degree of chiral self-sorting. The self-assembly process proceeds in a highly selective narcissistic self-recognition manner to give only homochiral supramolecular M2 L4 cages, which were characterized by ESI-MS, NMR, and electronic circular dichroism (ECD) spectroscopy, as well as by single-crystal XRD analysis.