Effect of Amino- and Phosphorus-Containing Alkylene Substituents on the Complexing Ability of Phosphorus-Containing Cationites with Respect to Indium and Gallium Cations

The coordination properties of additional basic and acidic groups in phosphinic acid macroporous ionites are controlled by varying their nature and mutual arrangement during the sorption of indium and gallium cations. Patterns of the targeted change in the acidic and electron-donating properties of polydentate moieties are determined along with its effect on the sorption-selective characteristics of ionites, excluding that of matrix selectivity. It is shown how substituents in the form of proton-accepting anionogenic and phosphinic acid groups influence the sorbability of trace elements by raising the ion-coordinating strength of the phosphoryl system. It is established that the advantageous spatial structure of diphosphonic cationites and the effect of an additional ring increase the degree of sorption, especially for gallium in sulfuric acid solutions. Modifying ionites by replacing substituents in the phosphine center is an effective way of creating new chelating sorbents.