Bifunctional fluorescent thiacalix[4]arene based chemosensor for Cu2+ and F− ions

A new thiacalix[4]arene based fluorescent sensor bearing two dansyl groups has been synthesized in cone conformation. In CH3CN:CH2Cl2 (1:1), the presence of Cu (II) induces the formation of a 1:1 metal:ligand complex, which exhibits increasing emission at 433 nm at the expense of the fluorescent emission of 1 centered at 504 nm. The detection limit of the sensor for Cu2+ is 2×10−7 mol L−1. For anion sensing, 1 shows a high selectivity for fluoride ions over other anions tested.