Etude electrochimique de l'iode et de ses derives en solution dans la pyridine variation des proprietes d'oxydo-reduction en fonction du pH

The electrochemical behaviour of iodine and redox derivatives in solution in pyridine was studied by the use of voltammetric method. By controlling the pH value, it is possible to establish the normal apparent thermodynamic diagram of stability of iodine in this solvent. In acid media, the four chemical species I^?, I^?₃, I₂ and I⁺ are stable; their respective stability constants are evaluated. In basic media, one observes the disproportionation reaction of iodine, at first into triodide and into a base complexing with iodine in (I⁺), then into iodide and iodate. A salt of positive univalent iodine was isolated by neutralizing I⁺ with an excess of tetraethylammonium hydroxide.