New heavy metal ion-selective macrocyclic ligands with mixed-donor atoms and their extractant properties

Synthetic procedures for new macrocyclic diamides with N2S4O3- and N2S5O3-donors were given. The corresponding macrocyclic ligands were prepared by reaction of NaBH4 with the macrocyclic diamides in the presence of boron triflouride ethyl etherate in dry tetrahydrofuran. The solvent extraction method was used to evaluate metal-ion binding properties of the new ligands. The values of the extraction constants (log Kex) and the complex compositions were determined for the extracted complexes. The solvent extraction experiments suggested that the reduced N2S5O3-donor macrocycle has Ag+ selectivity compared to Pb2+, Co2+, Ni2+, Mn2+, and Cd2+ for chloroform as organic solvent.