Synergic Extraction of Divalent Transition Metals With Mixtures of 1-Phenyl-3-Methyl-4 Benzoyl- Pyrazol-5-One and Crown Ethers in Presence of Alkali or Alkaline Earth Ions

The extraction of divalent transition metals (M = Cu, Zn, Co, Cd) with mixtures of 1-phenyl-3-methyl-4-benzoylpyrazol-5-one (HL) and crown-ethers (E = B15C5, 18C6, DC18C6, DB18C6, DC24C8, DB24C8 with B = benzo, DB = dibenzo, DC = dicyclohexyl) in chloroform has been studied. From 1.0 M K aqueous solutions, EK.ML3 ion pairs have been extracted with 18C6 - type crown ethers that have a good correspondence between their cavity size and the K+ diameter, _and with M = Co and Cd, metals with a higher stability of the ML- anion. With B15C5, which has a cavity size too small to accomodate K+, the synergic extraction of Co is explained by the formation of E2.K.CoL3. Both CoL2E and EBa(CoL3.) 2 (E = DBl8C6)were extracted from 0.33M Ba(No3 ) 2. In all otHer experiments - extractions from 1.0M LiCl, NaCl, NaNO with B15C5