A naphthalimide-based fluorescent sensor for halogenated solvents

Abstract

A fluorescent sensor for halogenated solvents termed AMN is reported. AMN shows strong fluorescence in most halogenated solvents (QE > 0.1) but weak fluorescence (QE<0.01) in most non-halogenated solvents. In chlorinated solvents, the fluorescence intensity decreased with the reduction of chlorine content. On the contrary, in brominated solvents the fluorescence intensity increased with the reduction of bromine content. It is worth mentioning that AMN displayed fluorescence emission centered at 520 nm in CCl₄ with a quantum yield of 0.607, at 556 nm in CHCl₃ with a quantum yield of 0.318, at 584 nm in CH₂Cl₂ with a quantum yield of 0.128, whereas in CHBr₃ was centered at 441 nm with a quantum yield of 0.012. AMN was shown to have the ability to differentiate CCl₄, CHCl₃, CH₂Cl₂ and CHBr₃ halogenated solvents.