2,2'-PYRIDIL-MONO AND 2,2'-PYRIDIL-BIS-(2-PYRIDYLHYDRAZONES) AS SOLVENT EXTRACTANTS FOR COPPER(II), NICKEL(II), AND COBALT(II)

2,2′-Pyridil, also known as 2,2′-dipyridylglyoxal, has been condensed with either 1 or 2 mol of 2-pyridylhydrazone to form 2,2′-Pyridil-mono-(2-pyridylhydrazone) (PymPH) and 2,2′-Pyridil-bis-(2-pyridylhydrazone) (PybPH). These molecules have been studied as solvent extracting agents for Cu(II), Ni(II), and Co(II) from perchlorate media into MIBK. In the pH range 4-6 all ions are extracted with efficiencies of 80-99%, and are ion-paired. Other equilibria data including stoichiometries, effect of pH, ligand concentration, ionic strength, and metal ion concentration on the distribution coefficients are reported. In addition, comparisons between these two ligands and other 1,2-diketone mono- and bis-2-azaarylhydrazones are discussed. © 1990.