Two new isomerous fluorescent chemosensors for Al3+ based on photoinduced electron transfer

Abstract

Two new isomerous PET fluorescent chemosensors (L and L′) for Al3+ have been designed, synthesized and characterized. The two chemosensors exhibited fluorescence enhancement upon binding Al3+ in CH3CN by PET inhibition processes from both the sulfur and the nitrogen donors to anthracene. The job’s plot, Benesi–Hildebrand plot and 1H NMR titration experiments indicate that both chemosensors form a 1:1 complex with Al3+. The binding constants were calculated to be (1.432±0.186)×105 and (1.427±0.970)×105, respectively. Furthermore, the lowest detection limit for Al3+ in CH3CN was determined to be 4.8×10−7M and 2.2×10−7M, respectively.