Supramolecular Assemblies of Closely Stacked Antiaromatic Ni(II) Norcorrole Dimers via Homochiral and Heterochiral Self-Sorting

Stacking between aromatic π-systems is fundamental to the design of supramolecular assemblies. Recently, π–π stacked antiaromatic π-systems have received considerable attention as some antiaromatic compounds can form closely stacked structures with substantial in-termolecular orbital interactions, resulting in the emergence of stacked-ring aromaticity. Here, we report three covalently linked norcor-role dimers that self-assemble to form supramolecular architectures. A 2,2’-linked norcorrole dimer with 3,5-di-tert-butylphenyl groups forms a face-to-face stacked dimer both in solid and solution states via homochiral self-sorting. Its association constant in solution is (3.6 ± 1.7) × 105 M–1 at 20 °C. In the solid state, 3,3’-linked norcorrole dimers with 3,5-di-tert-butylphenyl and phenyl groups afford macro-cyclic and helical supramolecular assemblies via heterochiral and homochiral self-sorting, respectively. Notably, the subtle modification in the substituent resulted in a complete change in the structure of the aggregates and the chiral self-sorting mode. The present findings demonstrate that structural manipulation in antiaromatic monomer units leads to the formation of various supramolecular assemblies on the basis of the attractive interactions between antiaromatic π-systems.