Extraction of oxyanions with basic polymethine dyes from aqueous and aqueous-organic solutions: extraction-photometric determination of rhenium (VII) and tungsten (VI)

摘要

Characteristic properties of tile extraction of some oxyanions as ion pairs with basic polymethine dyes (derivatives of 1,3,3-trimethyl-3H-indolium) from aqueous and aqueous-organic solutions are studied. Using rhenium(VII) ion pairs as an example, the influence of the nature and concentration of the inert and active solvents in the mixture on extraction is revealed. It is demonstrated that ion pairs formed by multicharged oxyanions and polymethine dyes can be extracted from aqueous-organic solutions. Most important spectrophotometric characteristics have been calculated for colored extracts of ion pairs formed by some oxyanions and polymethine dyes. New procedures have been developed for the extraction-photometric determination of rhenium(VII) and tungsten(VI).