Bifunctional Fluorescent Calixarene Chemosensor for Both a Cation and an Anion
2005-02-18T00:00:00Z (GMT) by
A new fluorogenic cone calixtriazacrown-5 (1) bearing two pyrene amide groups and its structural analogue 2 have been prepared. Excited at 343 nm, 1 and 2 reveal excimer emissions at 448 and 472 nm, respectively. When heavy metal ions such as Pb2+ and Co2+ are bound to 1, the fluorescence intensities of both monomer and excimer are quenched whereas H bonding-assisted F- binding to 1 gives rise to a quenched monomer emission with little excimer emission change.