Cyclotris(paraquat-p-phenylenes)

Anamimoghadam, O., Cooper, J. A. ORCID: https://orcid.org/0000-0002-3981-9246, Nguyen, M. T., Guo, Q. -H., Mosca, L., Roy, I., Sun, J., Stern, C. L., Redfern, L., Farha, O. K. and Stoddart, J. F. (2019) Cyclotris(paraquat-p-phenylenes). Angewandte Chemie International Edition, 58 (39). pp. 13778-13783. ISSN 1433-7851 doi: 10.1002/anie.201907329

Abstract/Summary

Reported here is the synthesis, solid-state characterization, and redox properties of new triangular, threefold symmetric, viologen-containing macrocycles. Cyclotris(paraquat-p-phenylene) (CTPQT6+) and cyclotris(paraquat-p-1,4-dimethoxyphenylene) (MCTPQT6+) were prepared and their X-ray single-crystal (super)structures reveal intricate three-dimensional packing. MCTPQT6+ results in nanometer-sized channels, in contrast with its parent counterpart CTPQT6+ which crystallizes as a couple of polymorphs in the form of intercalated assemblies. In the solid state, MCTPQT3(.+) 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.