A Novel Ferrocene-Based Calix[4]arene as an Efficient Optical and Electrochemical Sensor for Highly Selective Fluoride Recognition

A new tetra ferrocene-triazole-amide functionalized calix[4]arene as an effective optical and electrochemical anion sensor was successfully synthesized in high yield. The structure of the resulted compound ( 5,11,17,23-tetra(ferrocenyl-1H-triazolo-acetamido)-25,26,27,28- tetrabutyloxycalix[4]arene, 6) was characterized with NMR spectra and elemental analysis. The anion binding properties of the compound in the presence of different anions were studied by various techniques (UV-Vis, fluorescence, cyclic voltammetry (CV) and H-1 NMR titration), which showed high selectivity and remarkable sensitivity toward fluoride ion (F-). The association constant (K-a) and the limit of detection (LOD) were determined to be 5.35x10(+8) M-2 and 2.98x10(-6) M, respectively. The results indicate this compound could act as an efficient sensor for fluoride anion in the presence of other common anions.