Colorimetric recognizing of biologically important anions based on anion-induced tautomerism of the sensor

Abstract

The anion sensing ability of compound 1 based on a novel 2,4-dinitrophenylhydrazone derivative was studied through "naked-eye" experiment, UV-Vis spectral titration, and 1H NMR titration. Sensor 1 was synthesized through a simple method with high yield. The solution of host 1 turned deep purple from light purple in the presence of the strong basic anions and turned yellow upon addition of the weak basic anions, respectively. The results could be explained on the basis of transfer of the tautomeric equilibrium of sensor 1 induced by anions with different basicity. Copyright © 2008 John Wiley & Sons, Ltd.