Benzimidazole-based fluorescent sensors for Cr 3+ and their resultant complexes for sensing HSO 4- and F -

Abstract

A benzimidazole-based receptor that selectively recognized Cr3þ without interference from other metal ions was synthesized in this study. The resultant Cr-complex recognized HSO4 and F via two approaches. HSO4 ions bound to the metal center, causing changes in the fluorescent spectra at different wavelengths, whereas F ions displaced Cr3þ, thereby switching ON the fluorescent spectra at the same wavelength.