Hydrobromic acid salts of new N, N, O tridentate ligands containing phenol, 2-[(2-Methylamino- ethylamino)-methyl]-phenol(H-MMP․2HBr), 5-Bromo-2-[(2-Methylamino-ethylamino)-methyl]-phenol (Br- MMP․2HBr), 5-Chloro-2-[(2-Methylamino-ethylamino)-methyl]-phenol(Cl-MMP․2HBr), 5-Methyl-2-[(2-Methylamino- ethylamino)-methyl]-phenol(Me-MMP․2HBr), 5-Methoxy-2-[(2-Methylamino-ethylamino)- methyl]-phenol(MeO- MMP․2HBr) and 1-[(2-Methylamino-ethylamino)- methyl]-naphthalen-2-ol(Nap- MMP․2HBr) were synthesized. The synthesized ligands were confirmed by C. H. N. atomic analysis, UV-visible and IR spectroscopies, 1H NMR, 13C NMR and mass analysis. The potentiometry study revealed that the proton dissociation constants(logKnH) of the synthesized ligands and stability constants (logKML, logKML2) of transition metal complexes of Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Pb(II) ions occurred in three steps and the order of the calculated overall proton dissociation constants(logβp) and stability constants (logKML) of ligands was Br-MMP․2HBr < Cl-MMP․2HBr < H-MMP․2HBr < Nap-MMP․2HBr < Me-MMP․2HBr < MeO-MMP․2HBr. The order showed a similar trend to that of Hammett substituent constants(δp). The synthesized ligands usually form 2:1(ML2) complexes with transition metal ions. The order of the stability constants of each transition metal ions was Co(II) < Ni(II) < Cu(II) > Zn(II) > Cd(II) > Pb(II).

The thiophene or furan-containing hexadentate ligands 1,12-bis (2-theophene)-2,5,8,11-tetraazadodecane(Thiotrien ․4HCl) and 1,12-bis (2-furan)-2,5,8,11-tetraazadodecane(Furatrien․4HCl) were synthesized as their tetrahydrochloride salt and characterized by EA, IR, NMR, and Mass spectrum. Their protonation constants (logKnH) and stability constants (logKML) for Cd2+, Pb2+, Zn2+ and Cu2+ ions were determined in aqueous solution by potentiometry and compared with 1,12-bis(2-pyridyl)-2,5,8,11-tetra-azadodecane(Pytrien) of pyridyl-containing ligand. The effect stability constants of ligands and metal ion for removal of heavy metals in aqueous solution were described.