Bimodal Calix[2]triazole[2]arene Fluorescent Ionophore

Abstract

Pyrene-appended calix[2]triazole[2]arene capable of bimodal sensing has been synthesized. Upon addition of Zn2+ (or Cd2+), it selectively exhibits an enhanced monomeric emission (similar to 13-20-fold) over other metal ions. On the other hand, it displays excellent selectivity for Fe2+ over other metal ions (even over Fe3+) from the angle of excimeric emissions (10-fold enhancement). Density Functional Theory (DFT) based theoretical calculations distinguished the bimodal activity of the probe and supported the experimental observations.