Spectrophotometric determination of the pseudohalide 1,2,3,4-thiatriazol-5-thiolate ion, CS(2)N(-)(3).
A critical study of the analytical methods available for the CS(2)N(-)(3) ion is reported. A modification of the argentimetric method is proposed. An oxidative study gave evidence of various steps corresponding to incompletely oxidized intermediates. The absorption maximum of the 1,2,3,4-thiatriazol-5-thiolate ion at 313 nm, with molar absorptivity of 7.4 x 10(-3)1.mole(-1).cm(-1) is utilized to develop a new analytical method. The spectrophotometric procedure is rapid and free from interference by many ions. A value of 1.51 +/- 0.02 was found for pK of HCS(2)N(3) at an ionic strength of 1.00M and at 25 degrees . The spectrum of CS(2)N(-)(3) is changed by increasing acidity of the medium, due to the formation of HCS(2)N(3); an isosbestic point is observed at 251 nm.
Neves
E A
EA
Instituto de Química da Universidade de São Paulo, Brasil.
Franco
D W
DW