Synthesis and metal-ion binding properties of new N2S4- and N2S5-donor macrocycles

Synthetic procedures for new N2S4- and N2S5-donor macrocycles (2 and 4) were given. The ligands were prepared by the reaction of NaBH4 with the appropriate macrocyclic diamide in the presence of boron trifluoride ethyl etherate in dry tetrahydrofuran (THF). Solvent extraction method was used to evaluate metal-ion binding properties of the new ligands. The solvent extraction experiments suggested that the reduced macrocycles have Ag and H2+ selectivities compared to Pb2+, Co2+, Zn2+, Ni2+, Cu2+, Mn2+ and Cd2+ ions. The extraction constants (log K-ex) and complex compositions were determined for Ag+ and Hg2+ complex of compound (4).