Stable and Fully-Oxidized Methylene-Bridged Macrocyclic Phenothiazine Polyradical Cations

Macrocyclic arenes represent one of the most important and intensively investigated entities in supramolecular chemistry. However, research on the redox activities of macrocyclic arenes, especially their isolable and crystalline polyradical analogues, has been rarely reported. Here, we present the synthesis, redox activity, and application of methylene-bridged macrocyclic phenothiazines, where polyradical cations are successfully isolated and unambiguously characterized for the first time. This research provides an effective method for preparing polyradical macrocycles, which expands the scope of investigation into macrocyclic arenes and their potential applications.