SUPRAMOLECULAR POLYMERIC RECEPTORS FOR BINDING ALKALI METAL IONS

Polymeric derivatives of crown ethers attract significant research interest due to their high specificity in complex formation and broad potential applications in various technological processes. Compared to their low-molecular-weight analogs, these polymeric macroligands offer advantages such as reusability, ease of separation from solutions, enhanced sorption and complexation properties. They are used in sorption, ultrafiltration, sensing, chromatography, and other processes requiring selective interaction with metal ions. This study investigates the synthesis and properties of new polysulfones containing crown ether fragments (DB12K4, DB18K6, DB24K8, DB30K10), obtained by polycondensation of bis(chlorosulfonyl) derivatives of crown ethers using Friedel–Crafts catalysts (FeCl3, AlCl₃, SnCl₄). The influence of catalyst type and concentration, temperature, and solvent on the yield and viscosity of the resulting polymers was examined. The highest yield was achieved using catalytic amounts of FeCl3 at 1200C. IR spectroscopy and thermogravimetric analysis confirmed the high thermal stability of the synthesized polymers (up to 600°C). Sorption studies demonstrated that the selectivity and efficiency of alkali metal ion extraction depend on the size of the crown ether cavity, the nature of the solvent, and the macrocycle structure. It was shown that polymeric crown ethers exhibit higher complexation ability than their low-molecular counterparts. Thus, new thermally stable polycrownsulfones with high selectivity toward alkali metal ions were successfully synthesized for the first time, indicating their promising applications in analytical chemistry and separation technologies.