Solvatation et complexation des métaux dans les mélanges eau – fluorure d'hydrogène. Sn, Cd, Pb et Tl

The behavior of tin and thallium has been studied in water–HF mixtures. The formation of thallium fluoride complexes was not observed. Tin Sn2+ forms two complexes, SnF2 and SnF+, in mixtures containing less than 60% in HF. SnF2 is strong enough to prevent the formation of chloride complexes. SnF62− and SnF5− have been determined for Sn4+ in the same solutions. The relatively high strength of the tin fluoride complexes is reflected in the R0 (M) function. In fact, all the metals studied, Sn, Cd, Pb, and Tl, are less solvated in water–HF mixtures than in water, except for the case where the fluoride complex is strong, i.e., tin. HF2− seems to be the complexing species at high HF concentrations. Keywords: polarography, thallium, tin, cadmium, lead, hydrogen fluoride. [Journal translation]