Fluorescent chemosensor based-on the combination of julolidine and furan for selective detection of zinc ion

A new sensor 1-[[(2-furanylmethyl)imino]methyl]-2-hydroxyjulolidine (1) based on the combination of julolidine and furan groups was designed and synthesized as a Zn^{2 +} selective fluorescent chemosensor. Upon treatment with zinc ions, the complexation of 1 with Zn^{2 +} exhibited a pronounced enhancement in the fluorescence emission in methanol, while many other ions such as Mn^{2 +}, Co^{2 +}, Ni^{2 +}, Cd^{2 +}, Hg^{2 +}, Na⁺, K⁺, Mg^{2 +}, Ca^{2 +}, Al^{3 +} and Ag⁺, had no influence. Notably, this chemosensor could distinguish clearly Zn^{2 +} from Cd^{2 +}. The 1:1 binding mode of the 1-Zn^{2 +} complex was drawn, based on UV-vis titration, fluorescence titration, Job plot and ESI-mass spectrometry analysis.