Synthesis and evaluation of the chromo-fluorogenic recognition ability of imidazoquinoline derivatives toward ions

Abstract

[EN] Four imidazoquinolines functionalized with different carbocycles and heterocycles were synthesized and characterized. Acetonitrile solns. of the four receptors presented absorption bands in the 330-370 nm range. The four probes were also emissive with fluorescence bands in the 390-460 nm interval. In a 1st step, the chromo-fluorogenic behavior of the four probes was evaluated in the presence of selected anions. Addn. of F- induced the appearance of a new red shifted absorption band together with a moderate quenching of the fluorescence in all four receptors. In a 2nd step, the UV-​visible and emission behavior of the four receptors in the presence of cations was tested. Addn. of Hg2+, Cu2+, Co2+, Fe3+, Fe2+, Zn2+, Pb2+, Cd2+, Cr3+ and Al3+ induced a similar optical change in all four receptors (appearance of a broad red shifted absorption band together with a remarkable quenching of the emission band).