Liquid–liquid extraction of cationic metal complexes with p-nonylphenol solvent:: Application to crown and thiacrown ether complexes of lead (II) and copper (II)

The hydrophobicity of alkylphenols increases with an increase of alkyl chain length; p-nonylphenol floats on the surface of aqueous solution as a hemispherical droplet. We have found that cationic metal complexes with crown ether and thiacrown ether ligands can be quantitatively extracted into the p-nonylphenol phase in the presence of small anions e.g. butyrate rather than bulky counter anions. The coordination ability of p-nonylphenol solvent is ascertained by the extraction data on lead (II)-crown ether and copper (I, II)-thiacrown ether complexes. The potential usefulness of p-nonylphenol as an extraction solvent in ion-pair system is shown.