Cyclotris(paraquat-p-phenylenes)

摘要

Reported here is the synthesis, solid-state characterization, and redox properties of new triangular, threefold symmetric, viologen-containing macrocycles. Cyclotris(paraquat-p-phenylene) (CTPQT(6+)) and cyclotris(paraquat-p-1,4-dimethoxyphenylene) (MCTPQT(6+)) were prepared and their X-ray single-crystal (super)structures reveal intricate three-dimensional packing. MCTPQT(6+) results in nanometer-sized channels, in contrast with its parent counterpart CTPQT(6+) which crystallizes as a couple of polymorphs in the form of intercalated assemblies. In the solid state, MCTPQT(3(.+)) exhibits stacks between the 1,4-dimethoxyphenylene and bipyridinium radical cations, providing new opportunities for the manipulation and control of the recognition motif associated with viologen radical cations. These redox-active cyclophanes demonstrate that geometry-matching and weak intermolecular interactions are of paramount importance in dictating the formation of their intricate solid-state superstructures.