Phenol/phenolate-dependent on/off switching of the luminescence of 4,4-difluoro-4-bora-3a,4a-diaza-s-indacenes

Abstract

Boradiazaindacenes 1 and 2 bearing phenolic subunits show deprotonation/protonation dependent fluorescence off/on-switching; the lack of emission of the phenolate forms is attributed to photoinduced electron transfer (PET) between the phenolate and indacene subunits.