Triptycene based chemosensors for selective detection of mercury(II)/iron(III) in aqueous medium

• Facile synthesis of 2,6,14- and 2,7,14-triptycenetripropiolic acids in high yields.
• Unique examples of triptycene based tripodal chemosensors.
• Selective and specific detection of Hg2+/Fe3+ in pure aqueous media.
• Low detection limits for Hg2+/Fe3+ using fluorescence (turn off) spectroscopy.
• pH dependence of fluorescence quenching of receptors has been investigated.

Synthesis and characterization of two trisubstituted triptycene derivatives in high yields are being reported. Aqueous solutions of sodium salt of 2,6,14- and 2,7,14-triptycenetripropiolic acids (1c and 2c) have shown high selectivity for Hg2+ and Fe3+ ions, through quenching of fluorescence intensity, when tested in presence of other metal ions in pure aqueous medium. In addition, pH dependence of fluorescence quenching has been studied. Binding stoichiometry between probes and metal ions (Hg2+ and Fe3+) has been studied using Job’s plot, and corresponding association constant has been evaluated. 1c and 2c are the unique examples of triptycene based tripods that act as chemosensors for selective detection of metal ions.

Two new trisubstituted triptycene derivatives (2,6,14- and 2,7,14-triptycenetripropiolic acids) were synthesized and characterized. Sodium salt of these tricarboxylic acids have shown high selectivity for mercury(II) and iron(III) ions, through quenching of fluorescence intensity, in pure aqueous medium. In addition, pH dependence of fluorescence quenching has been studied.Figure optionsDownload as PowerPoint slide