EXTRACTION OF HCLO4 AND HREO4 BY DILUTE SOLUTIONS OF TRIBUTYL PHOSPHATE IN BENZENE SYM-TRIETHYLBENZENE AND CHLOROFORM

The extraction of HClO4 or HReO4 into dilute solutions of tributyl phosphate (TBP) in benzene, sym-triethylbenzene, and chloroform has been studied. In the benzene and chloroform systems only a two-TBP acid complex was found, while in triethylbenzene a three-TBP acid complex was also found, depending on the TBP concentration. It is suggested that in all cases the extracting species is based upon a hydronium ion core which is ion paired to the anion, i.e., nTBP·H3O+·pH2O⋯ClO 4-. In benzene, the value of n = 2 and p is ∼2. It is also suggested that the variation in coordination number and in extraction coefficients in these diluents and in those studied in the previous paper can be plausibly explained on the basis of the properties of the diluents.