Liquid-liquid distribution of ion associates of hexabromotellurate (IV) with quaternary ammonium counter ions

The distribution behavior of ion associates (Q⁺)₂. TeBr₆²⁻ of TeBr₆²⁻ with quaternary ammonium cations (Q⁺) between aqueous phase and two organic phases (1,2-dichloroethane (DCE) and chloroform (CF)) was examined, and the extraction constants (log K_ex) were determined. The extractability with long-chain alkyltrimethylammonium cations (group I) is greater than that with symmetrical tetraalkylammonium cations (group II) in the 1,2-dichloroethane extraction system and the difference in log K_ex for two cations (one of each type) with the same number of carbon atoms was about 3 on the average. The contributions of a methylene group in the cations of groups I and II to log K_ex were found to be 0.431.10 and about 0.74 on the average. Among the ion associates examined, the extractability of the extracting solvent was in the DCE>CF; the difference in log K_ex was about 5 on the average.