The isomer space of face-capped coordination cages based on square planar metal complexes and low-symmetry ligands

Abstract

Face-capped coordination cages based on square planar metal complexes and low-symmetry ligands can form isomers, which differ in the relative orientation of the bridging ligands. We have used Burnside's lemma to enumerate the possible isomers for tri-, hexa-, and octanuclear cages and ligands of variable symmetry. The number of distinct isomers for these systems was found to range between 3 and 70 479, with chiral cages being generally more common than achiral ones. Strategies to achieve orientational self-sorting during the assembly of such cages are discussed.