The recognition and sensing of anions by a novel phenanthroline-bridged diamide

A novel neutral anion recognition receptor 1 with the additional capability of selectively sensing anionic guest species has been synthesized and examined for its anion-binding abilities by UV–vis absorption spectroscopy. The results of nonlinear curve fitting and Job plot indicate that 1 forms 1:1 stoichiometric complexes with fluoride, chloride, bromide, iodide, and acetate, respectively. Their UV–vis absorption spectra in DMSO indicate the presence of anions such as F –, Cl –, Br–, I–, and AcO– with high affinity ability and selectivity toward F –, and also show dramatic colour changes from colourless to yellow in the presence of TBAX (1× 10–5 mol/L, X= F –, Cl –, Br–, I –, and AcO–). Receptor 1 has almost no affinity abilities for H2PO4– and OH–. Key words: phenanthroline-bridged diamide, synthesis, UV–vis spectrum, anion recognition.