Origins of “on—off” Fluorescent Behavior of 8‐Hydroxyquinoline Containing Chemosensors.

Abstract

Title hydroxyquinoline derivatives (I) are used to probe the mechanism of non-radiative relaxation of the fluorophores in fluorescent chemosensors like (II). It is shown that both photo-induced proton transfer and photo-induced electron transfer processes can cause fluorescence quenching in these molecules. Proton shift from hydroxy to amino group in compounds (II) accompanied by complexation of metal cations inhibits the relaxation processes and, thus, allows for detection of metal cations by fluorescence. -(BRONSON, R. T.; MONTALTI, M.; PRODI, L.; ZACCHERONI, N.; LAMB, R. D.; DALLEY, N. K.; IZATT, R. M.; BRADSHAW, J.