Establishment of the structure of hydrate-solvate complexes of iodine extracted from model aqueous solutions in the system I2 – NaCl – Н2О – tributylphosphate /isooctane

The equilibrium parameters of the extraction of iodine from aqueous model solutions of various compositions have been determined and the influence of the background mineralization of the raffinate has been revealed. The effect of the isooctane/tributylphosphate (TBP) ratio on the extraction of iodine from aqueous solutions with different ionic strengths has been determined by the isomolar series method. The hypothetical composition of hydrate-solvate complexes has been established both experimentally and using computer modeling tools. For quantum chemical calculations, optimization of the geometric parameters of the constructed structures has been carried out within the framework of the density functional theory (DFT) method, with the exchange-correlation functional B3LYP, with the LANL2DZ basis. A synergistic effect has been revealed in the system iodine – isooctane – TBP – water, which is achieved through the interaction of iodine with TBP through a mixed mechanism: solvate and hydrate-solvate. The composition of hydrate-solvate complexes in this case should look like: [H3O(H2O)3 ∙ТBP]+I2Cl− or [H3O(H2O)3 ∙ ТBP]+ICl2−.