Engineering of unsubstituted quinoid-like frameworks enabling 2 V vs. Li+/Li redox voltage tunability and related derivatives

A criterion for redox voltage tuning (0.96-2.96 V vs. Li+/Li) was derived from DFT calculations on quinoneazine and analogues (C/O replacing N). As rationalized through spin-charge distributions and energetic criteria, high-low voltage implying a bridge with delocalized-localized bond nature mainly originates from ring stabilization. Established guidelines serve to propose optimal derivatives.