SOLUBILITY OF DIARY[DIALKYLCARBAMOYLMETHYL]PHOSPHINE OXIDES IN NITRIC-ACID SOLUTIONS

A method for determining solubility of neutral bidentate organophospho rus compounds (NBOPCs), in particular diaryl[dialkylcarbamoylmethyl]ph osphine oxides (CMPOs), in aqueous solutions of acids has been propose d. The method is based on the considerable increase in extraction of s ome elements - transplutonium (TPE), rare-earth (RE), iron(III), urani um(VI), etc. - from acid solution upon addition of small amounts of pe rchloric acid. The concentration of CMPO in an aqueous acid solution i s determined by the following procedure: aliquots of HClO4 and any of the above radioactive isotopes were added to CMPO solution in nitric ( or other) acid, the isotope was extracted with pure solvent as CMPO co mplex, and then the concentration: was indirectly determined from the distribution coefficient using log D-el = f(\R\) calibrating curve. Th e curve was plotted from the results of extraction of the isotope from the mixture of perchloric acid and nitric acid in which the concentra tion of the reagent was determined. The solubilities of three phenyl-s ubstituted at the phosphorus atoms CMPOs with butyl, octyl, and isoamy l substituents at the nitrogen atom were measured in 3 M nitric acid.