A new imidazolium/sulfonamide linked ferrocene-dansyl dyad for dual-channel recognition of anion

Abstract

A new ferrocene-dansyl dyad (Fc-DAS), in which the ferrocene unit and the dansyl fluorophore are linked by the imidazolium and the sulfonamide groups, has been designed. The recognition ability of probe toward various anions (H2PO4−, F−, Cl−, Br−, I− and AcO−) has been investigated by fluorescent spectrum and electrochemical techniques (differential pulse voltammetry and cyclic voltammetry). This probe shows fluorescent sensing of F− over other anions with a quenching effect in CH3CN solution. However, the electrochemical experiments reveal that the binding of H2PO4−, F− and AcO− anions leads the potential of probe a cathodic shift, with the shift magnitude H2PO4− > F− > AcO−. Furthermore, the binding mechanisms between Fc-DAS and anions have been investigated using 1H NMR titrations and density functional theory (DFT) calculations.