α,α′-Diamino-p-quinodimethanes with Three Stable Oxidation States

Herein, we report the rational design, synthesis, and characterization of alpha,alpha'-diamino-substituted-p-quinodimethanes, which are a group of partially substituted p-quinodimethanes. These exhibit two reversible one-electron redox steps and electrochromism in the ultraviolet, visible, and near-infrared regions. We were able to isolate the crystalline compounds of all three oxidation states: neutral, radical cation, and dication. The obtained results not only create the bridge between p-quinodimethane and alpha,alpha,alpha',alpha'-tetrasubstituted-p-quinodimethane, but also demonstrate the straightforward modular approach for the synthesis of pi-conjugated open-shell compounds.