A sandwich anion receptor by a BODIPY dye bearing two calix[4] pyrrole units

A novel dicalix[4] pyrrolyl-substituted 4,4-difluoro-4-bora-3a, 4a-diaza-s-indacene (BODIPY) dye I with an absorption peak at approximately 670 nm and an emission peak at about 690 nm was prepared. As an anion receptor, I displayed a red shift in absorption spectra and fluorescence quenching in varying degrees in the presence of F(-), AcO(-), H(2)PO(4)(-), or Cl(-). Compared with the parent calix[4] pyrrole, a representative anion receptor, I exhibited a stronger affinity to these anions due to the formation of a sandwich complex through multiple hydrogen-bonding interactions. (C) 2011 Institute of Chemistry, Slovak Academy of Sciences