THE INFLUENCE OP THE DILUENT ON THE DISTRIBUTION BEHAVIOR OF OCTYL(PHENYL)-N,N-DIISOBUTYLCARBAMOYLMETHYLPH0SPHINE OXIDE

Abstract

ABSTRACT The degree of Interaction or compatibility of the neutral bifunctional extractant 0фD(lB)CMP0 with a diluent was determined by measuring the distribution ratio of the extractant between two phases. The distribution ratio, DCMPO, was highest in chloro-carbon and aromatic diluents with small molar volumes and lowest in normal paraffinic hydrocarbon diluents with large molar volumes. An approximate correlation between DCMPO in a variety of diluents and the solubility parameter (𝛅) of the diluent was obtained using equations for regular solutions and b.delta;H2o =34.8. A much better correlation was obtained between DCMP0 find an empirical solution parameter. It was found that the distribution ratio of diisobutylcarbamoylmethylphosphine oxides increased by 3 orders of magnitude as the basicity of the phosphoryl group on the extractant was increased by the replacement of two phenyl substi-tutents on the phosphorus atom with two octyl groups The influence of TBP as a phase modifier in 0фD (iB)CMPO -diluent systems was also studied. No evidence was found for complex formation between CMPO extractants and TBP. Changes in DCMPO on addition of TBP appear to be essentially solvent effects. The interaction between 0фD(1B)CMP0 and diluents also explains, to some extent, variations of DAM using different diluents.