Photochemical behaviour of Tc$_2$OCl$_{10}^{4–}$ and Tc$_nO_y^{4n–2y+}$ in chloride media
Résumé
The stabilities of the technetium polymers Tc2OCl104− and TcnOy4n−2y+ have been studied under light irradiation in 3 M chloride media with a pH range from 0 to 1.3. It has been shown that under irradiation, Tc2OCl104− is not stable and undergoes dissociation to TcCl5(H2O)- at pH = 0 and pH = 0.3. At pH = 1, irradiation of Tc2OCl104− leads to a stationary state involving TcCl5(H2O)- and Tc2OCl104−. At pH = 1.3, TcnOy4n−2 y+ remains stable under irradiation. Under light irradiation, the predominance diagram of Tc(IV) species obtained from Tc2OCl104− aquation in a pH range from 0 to 1 is drawn. The chemical behaviour of Tc2OCl104− and the influence of the light on the condensation of Tc(IV) and solubility of TcO2· x H2O are discussed.