The synthesis and characterization of 22-membered diazapentathia macrocycles and investigation of their ion extraction capability from aqueous media

Two new macrocyclic ligands, (5) and (6), containing nitrogen-sulfur donor atoms were designed and synthesized in a multi-step reaction sequence. Ion extraction capability of macrocycles (5) and (6) were investigated involving solvent extraction of metal picrates such as Ag+, Hg2+, Cd2+, Zn2+, Cu2+, Ni2+, Mn2+, Co2+ and Pb2+ from aqueous phase to the organic phase. The metal picrate extractions were carried out at 25 +/- 0.1 degrees C and extractions were measured by u.v.-visible spectrometry. The extractability and selectivity of the mentioned metal picrates were evaluated depending on the organic solvents used for extraction. The extraction constant (log K-ex) and the complex composition of each metal complex were determined using spectroscopic methods.