Diverse Postfunctionalization of Open-Shell Diradicaloids and Impact of Conjugated Functional Substituents on Optoelectronic Properties

Organic radicals are usually incapable of postfunctionalization for structure expansion and optoelectronic property optimizations. Herein, based on a sulfone-embedded skeleton derived from Chichibabin's hydrocarbon, we showcase the regioselective bromination and further postmodifications of open-shell diradicaloids via diverse palladium-catalyzed nucleophilic substitution, Sonogashira coupling, and Stille coupling reactions. Such facile structural expansions yielded a series of conjugated singlet diradicaloids, showing finely tuned physicochemical characteristics, versatile crystalline-state molecular configurations and packing modes, and impressive charge-carrier mobility of 1.5 cm²/V·s.