Phosgene invites selective switch-on fluorescence at ppm concentrations in a Betti base by hindering 2-way PET

Abstract

We have developed a simple, targeted Betti base, BB for the chemodosimetric fluorescent sensing of poisonous phosgene gas via the formation of a fluorescent carbamate species, BBC. The probe is found to be extremely quick (reaction time <1 min) and sensitive with an appreciably low detection limit of 0.40 μM and is amenable to sensing very low gas phase phosgene concentrations of ∼5 ppm in the solid state when supported upon TLC sticks. Fluorescence changes are instantaneous (∼20 s), vivid and easily observable by the naked eye under a handheld UV lamp.