A highly selective colorimetric and fluorescent probe for Cu2+ and Hg2+ ions based on a distyryl BODIPY with two bis(1,2,3-triazole)amino receptors.

A new distyryl boron dipyrromethene (BODIPY) with two bis(1,2,3-triazole)amino substituents has been prepared by typical Knoevenagel condensation followed by click reaction. The compound selectively binds to Cu(2+) and Hg(2+) ions in CH(3)CN/H(2)O (1:1 v/v) to give remarkably blueshifted electronic absorption and fluorescence bands as a result of inhibition of the intramolecular charge-transfer process upon binding to these metal ions. The color changes can be easily seen by the naked eye. The binding stoichiometry between this probe and Cu(2+) ions has been determined to be 1:2 by a Job plot of the fluorescence data with a binding constant of ((6.2±0.6)×10(9)) M(-2). The corresponding value for Hg(2+) ions is about sixfold smaller.