Detection and identification of nucleophiles through a PET-like luminescence turn-on mechanism

A new method for the detection and identification of nucleophiles based on a luminescence turn-on mechanism is presented. Electrophilic luminophores bearing a heavy atom as a leaving group are applied to the detection and identification of nucleophiles using a PET-like method. The presence of the heavy atom on the electrophilic luminophore induces heavy atom luminescence quenching through spin-orbit coupling and increased S1 → T1 intersystem crossing efficiency. Upon reaction with a nucleophile the heavy atom is replaced by the nucleophile and the luminescence of the luminophore is regained. The potential of this approach is demonstrated by detecting and identifying various nucleophiles using 9-anthrylmethyl 2-iodoacetate and N-(9-anthrylmethyl)-2-iodo- acetamide. The two poorly luminescent systems turn-on upon reacting with nucleophiles both in solutions and in the solid-state (films).