Anion sensors based on β,β′-disubstituted porphyrin derivatives

The synthesis of a disulfonamide appended porphyrin receptor (1) for anionic guests is presented. The distinct attribute of the receptor, compared to other porphyrin based receptors, centers on the attachment of the anion binding site to the porphyrin chromophoreʹs β-positions through a polycyclic conjugated linkage. UV–vis and 1H NMR spectroscopy has been utilized to detect the binding of a variety of anions such as the halides, dihydrogen phosphate, hydrogen sulfate, and acetate. From these spectroscopic investigations, the strength of anion binding has been determined.