Cu-Catalyzed Direct Arylation Polycondensation Achieving Ultrahigh μC* Organic Mixed Conductors

Organic mixed ionic-electronic conductors (OMIECs) are emerging semiconductors for energy storage, neuromorphic engineering, and biocompatible electronics. They are generally synthesized by Pd-catalyzed cross-coupling, raising synthetic complexity and cost concerns in the pursuit of efficient synthesis of OMIECs. In this research, a Cu-catalyzed direct arylation polycondensation (Cu-DArP) is developed to simplify the preparation of OMIECs. Motivated by diazaperylene ligands, this methodology features Pd-free, alternating conjunction of aryl halides and aromatic hydrocarbons, circumventing the adoption of precious metals and organometallic nucleophiles. Cu-DArP is independent of substrate structure, and it is generalized to the successful preparation of at least a dozen mixed-transporting polymers. Intriguingly, the Cu-DArP catalysis system displayed high reactivity and yield for the synthesis of these diketopyrrolopyrrole (DPP)-based OMIEC polymers, confirming the compatibility of diazaperylene with copper. Hence, Cu-DArP provides tremendous opportunities for screening high μC* (represents the product of charge carrier mobility and volumetric capacitance) OMIECs. Especially, the resultant OMIEC with a DPP-thienopyrroledione skeleton displayed a mobility of 6.25 cm² V^-1 s^-1 and an ultrahigh μC* of 876 F cm^-1 V^-1 s^-1. As a perspective, Cu-DArP would provide solutions to toxic metal residues and challenges from the adoption of organometallics in existing cross-coupling polycondensations, thus presenting a trustworthy alternative for next-generation OMIEC synthetic methodology.