An acidic pH fluorescent probe based on Tröger's base. Issue 88 (7th December 2017) - Yuan, Chunxue
Abstract : A pH fluorescent probeTBPP incorporating an amine moiety and pyridine group through Tröger's base linker was designed and synthesized. The absorption and fluorescence titrations indicated that it can serve as a sensitive probe for pH measuring. Abstract : A novel pH fluorescent probe 2, 8-(6 H, 12 H -5, 11-methanodibenzo[ b, f]diazocineylene)-di( p -ethenyl-pyridine) (TBPP ) incorporating an electron-donating amine moiety and electron-accepting pyridine group through Tröger's base linker was designed and synthesized.TBPP exhibits an intramolecular charge transfer effect caused by the donor–acceptor interaction between its amine and pyridine units. Its emission can be reversibly switched between blue and dark states by protonation and deprotonation. Such behavior enables it to work as a turn-off fluorescent pH sensor in solution state. 1 H NMR spectroscopy analysis suggests that the change in electron affinity of the pyridinyl unit upon protonation and deprotonation is responsible for such sensing processes.