Azocalix[4]arenes as Extractant for Hg+ and Hg2+, or Cr3+Cations

This article describes extraction properties of mono- (A1-A8) and di- (B1-B8) substituted azocalix[4]arene analogues. The ionophore solvent extractions of alkaline-earth (Sr2+), basic metal (Pb2+) and transition metal cations (Ag+, Hg+, Hg2+, Co2+, Ni2+, Cu2+, Cr3+) from aqueous phase to organic phase were carried out by azocalix[4]arene derivatives. It has been observed that they show a good extraction behavior toward selected heavy metal (Hg) and toxic metal (Cr), while A4 and B4 prefer Hg+, Hg2+ and Cr3+ among transition metal cations, respectively. The azocalix[4]arenes (A1-A8) and (B1-B8) are not efficient extractants for all of the selected metal cations, whereas A4 and B4 are selective only for Hg metal cation