Synthesis and metal ion binding properties of thiaaza crown macrocycles

Two new macrocyclic ligands (3) and (4), containing nitrogen-sulfur donor atoms, were designed and synthesized in a multi-step reaction sequence. The macrocycles (3) and (4) were used in 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 investigated at 25 ± 0.1 °C by using UV-visible spectrometry. The extractability and selectivity of the mentioned metal picrates were evaluated according to the organic solvents. The values of the extraction constants (log Kex) and the complex compositions were determined for the extracted complexes.