New dyes as reagents for the determination of rhenium

The reaction between the perrhenate-ion and the new Janus dyes - the Janus blue and the Janus green ''B'' - for determining rhenium contents by the extraction-photometric method has been investigated. The abive dyes were synthesized. A solution containing 102 mcg/1 of Re (7) was prepared by dissolving an accurately weighed portion of KReO4 in water. The Janus blue and the Janus green ''B'' were used as 0.1 and 0.05 % aqueous solutions respectively. The dyes were purified by a triple precipitation by sodium chloride or hydrochloric acid from a water solution. It was established that the interaction of ReO with said dyes is electrostatic in character, which is evidence of the formation of an ion associate. The determination of the degree of polymerization of resultant compounds has shown that the perrhenate of the Janus dyes in the organic phase is monomer. It was found that the interaction of the perrhenate-ion with the Janus dyes - Janus blue and Janus green ''B'' - yields an ion associate extractable at pH 1 and pH 3 by mixtures of benzene with dichlorethane (1/1) and of benzene with acetone (2/1) respectively. The proportion of components in the resultant ion associates was found to be, by the straight-line, the restricted-logarithmic and the relative yield methods, equal to 1/1. The majority of ions accompanying rhenium has no effect upon its determination. The method that has been developed is suitable for the determination of rhenium in thin films