EXTRACTION OF COPPER WITH -PHENYL-3'-METHYL-5'-HYDROXYPYRAZOL-4'-OYL)BENZENE AND WITH SOME -PHENYL-3'-METHYL-5'-HYDROXYPYRAZOL-4'-OYL)ALKANES IN CHLOROFORM

The extraction of copper with the new extractant phenyl-3'-methyl-5'-h ydroxypyrazol-4'-oyl)benzene, 'HL-mPh-LH', has been studied and compar ed to its extraction with the linear chain analogs, the henyl-3'-methy l-5'-hydroxypyrazol-4'-oyl-)alkanes, 'HL-n-LH' (n, number of methylene links). HL-mPh-LH is less lipophilic and more acidic than HL-n-LH. It appears under a keto-enol or diketo-amine tautomeric form in methanol and under an intramolecularly H-bonded chelated form in chloroform. B oth forms are observed in the solid state. Copper is extracted in chlo roform as Cu (L-mPh-LH)(2), Cu-2 (L-mPh-L)(2) Cu-2 (L-7-L)(2) and Cu ( L-rr-L), for n greater than or equal to 8, although third-phase format ion and loss of copper hinder the extraction with HL-4-LH. 1,2-dichlor oethane is a more efficient diluent than chloroform. The special advan tage of HL-mPh-LH is to reduce the main drawback observed with those e xtractants, ie, third-phase formation.