Preparation of complex transition metal polyiodoiodates without impurities of other phases

Composition and existence areas of transition metal (Mn, Fe, Co and Ni) polyiodoiodate complexes under their crystallization from aqueous solutions are determined. Formation of non-congruently soluble crystal polyiodoiodates of complex composition is ascertained when studying phase equilibria in MI2-L-I2-H2O systems where M are metals earlier indicated, L - is carbamide or acetamide. Polyiodoiodates obtained under equilibrium conditions, are characterized by phase purity (impurity content does not exceed 0.1%). Based on data obtained by physicochemical analysis method the techniques of complex polyiodoiodate synthesis under conditions close to equilibrium ones are developed