Two-way chromic interconversion of the 2,2′-biphenol-6,6′-diyl dication with 5H,10H-dioxapyrene or 9H,10H-4,5-dihydroxyphenanthrene

Abstract

Two-proton or two-electron transfer of the title biphenolic dication proceeds nearly simultaneously to induce 2,6′/2′,6- or 6,6′-bond formation to give dioxapyrene or dihydrophenanthrene derivatives, respectively, with vivid changes in color (halochromism and electrochromism).