PREPARATION OF NEUTRAL MIXED-LIGAND LANTHANIDE DI(2-ETHYLHEXYL) PHOSPHATE ACETATE COMPLEXES AND STUDY OF THEIR SOLUBILITY IN SOLUTIONS OF DEHP IN DECANE

A method was developed for preparation of solid compounds from saturat ed solutions of Ln(CH3COO)(3) (Ln = Pr, Nd, Sm, Eu, Gd, Tb, Er, Yb, an d Lu) in DEHP-decane mixture. Chemical analysis and IR spectroscopy sh owed that these compounds are neutral mixed-ligand lanthanide di(2-eth ylhexyl) phosphate acetate complexes. Their chemical composition corre sponds to the stoichiometric formula LnA(n)(CH3COO)(3-n), where A is d i(2-ethylhexyl) phosphate anion. These complexes have polymeric struct ure with presumable hexacoordination of lanthanide. The model of the m olecular structure of these complexes was developed. The solubility of di(2-ethylhexyl) phosphate acetates in DEHP-decane mixtures was studi ed as influenced by DEHP concentration. These results were used for de termination of composition of complexes formed in extraction of Ln(CH3 COO)(3) with solutions of DEHP in decane.