Effect of aniline derivatives on the extraction of cobalt with 1-phenyl-3-methyl-4-benzoylpyrazol-5-one in toluene

Abstract

The effect of aniline derivatives [4-methylaniline=4-toluidine, 3,4-dimethylaniline=3,4-xylidine, N,N-dimethylaniline and tribenzylamine (Am)] on the extraction of cobalt from sulphate, nitrate and perchlorate aqueous media of 1.0M ionic strength with 1-phenyl-3-methyl-4-benzoylpyrazol-5-one (HL) in toluene, has been quantitatively studied. With both primary amines a synergic effect was found owing to theAmH·CoL 3 ion pair extraction. TheAmH·CoL 3 average formation constant, from CoL 2 andAmH·CoL, was logK s =3.7 and 3.8 forAm=4-toluidine and 3,4-xylidine respectively. With N,N-dimethylaniline and tribenzylamine which are poorly protonated in the cobalt extractionpH range (4–6), no noticeable synergism was observed.