Synthesis and electrochromic behavior of a multi-electron redox-active N-heteroheptacenequinone

Abstract

We report a novel N-heteroheptacenequinone derivative (C₆OAHCQ) as a large π-conjugated framework. C₆OAHCQ shows good electron-accepting behaviour owing to eight electron-deficient imino-N atoms and two carbonyl moieties and excellent solubility in common organic solvents. When a potential between 0 and −2.20 V is applied, C₆OAHCQ is able to accept four electrons, which is more than fullerene C₆₀ (three electrons) could accept in this voltage range. Moreover, a solution of C₆OAHCQ and ⁿBu₄NPF₆ in CH₂Cl₂ exhibits a clearly reversible brown-to-green colour change, suggesting that C₆OAHCQ has potential as an electrochromic material.