Spectrophotometric Determination of Rhenium with Rubeanic Acid

Department of Chemistry, Jadavpur University, Calcutta-700 032. Manuscript received 6 May 1976 ; revised 18 September 1976 ; accepted 10 November 1976 Rubeanic acid produces a reddish-brown colouration with perrhenate in hydrochloric acid medium in presence of stannous chloride The complex has no absorption maximum in the range 370-600 mu. Studies have been made at the wavelengths of 410, 420, 450 and 460 nm since the reagent has no absorption at and above 410 nm. Beer's law is obeyed from 1-70 ppm of rhenium at all these wavelengths. Composition of the complex as determined by Job and molar ratio methods is found to be 1 : 1 at all the wave-lengths studied. Stability constant was calculated by the methods of Harvey and Manning, Leden and Rossotti and Rossotti. A large number of ions do not interfere in the determination of rhenium