Toward Möbius and Tubular Cyclopolyarene Nanorings via Arylbutadiyne Macrocycles.

By harnessing a highly efficient metal-catalyzed tandem cycloaddition reaction as the key benzannulation step, a series of cyclopolyarene nanorings of varied sizes are obtained from poly(arylene-butadiynylene) macrocyclic precursors, which can be synthesized relatively conveniently. Interestingly, due to the nonparallel bond connectivity of the repeat unit, unique Mobius topology is manifested by the cyclopolyarene nanorings composed of an odd number of repeat units, whereas cylindrical tubular structures with radial conjugation are formed with those consisting of an even number of repeat units.