Colorimetric and Ratiometric Red Fluorescent Chemosensor for Fluoride Ion Based on Diketopyrrolopyrrole

Three new diketopyrrolopyrrole (DPP) compounds are shown to be colorimetric and ratiometric red fluorescent sensors for fluoride anions with high sensitivity and selectivity. The recognition mechanism is attributed to the intermolecular proton transfer between a hydrogen atom on the lactam N positions of the DPP moiety and the fluoride anion.