Five new unsymmetrical aza-macrocycles, incorporating sp^2 and sp^3 nitrogen atoms as donor sites and with donor group-bearing side arms attached to the sp^3 nitrogen atoms, L^1-L^5, were synthesized. Their complexes with different kinds of metal cations such as Na^+, K^+, Cu^2^+, Co^2^+, Ni^2^+, Hg^2^+, Cd^2^+, Ru^2^+, were prepared and characterized by EA, IR, UV, NMR and MS spectroscopy. Some of the ligands can efficiently transport alkali and transition metal cations across an organic membrane with high transport selectivity ratio, especially in the case of Na^+/K^+ selectivity for L^1 and Hg^2^+/Ni^2^+ selectivity for L^2.

Key words: NITROGEN HETEROCYCLICS, SELECTIVITY, PYRIDINE, MERCURY COMPLEX, CADMIUM COMPLEX, COBALT COMPLEX, SODIUM COMPLEX, CROWN ETHER, ELEMENTAL ANALYSIS