Spectrophotometric Studies of Rhenium Complex with β-mercapto Cinnamic Acid

Department of Inorganic and Analytical Chemistry, Jadavpur University, Calcutta-700 032 Manuscript received 4 December 1980, revised 17 June 1981, accepted 14 September 1981 The reagent β-mercapto cinnamic acid forms a stable reddish-brown colour with rhenium solution formed by reducing an aqueous solution of KReO4 with stannous chloride in 0.5-1.25 N hydrochloric acid medium. The complex has no absorption maximum in the range 370-600 nm. At the arbitrarily chosen wavelength of 420 nm, the coloured solution obeys Beer's Law in the concentration range of 1-44 ppm of rhenium. Physicochemical studies indicate that the reagent forms 1 : 2 metal-ligand complex. The stability constant was determined by Leden and Rossotti's method and the log K values obtained are 10.90 and 10.45 respectively