Acid-Base and Complexing Properties of 2,2′-{[(Diisopropoxyphosphoryl)methyl]azanediyl}diacetic Acid

Abstract: Acid-base properties of 2,2′-{[(diisopropoxyphosphoryl)methyl]azanediyl}diacetic acid and its complexing ability towards alkaline-earth and transition metals have been studied by means of potentiometric titration. Comparative analysis of the determined stability constants and these of iminodiacetic and nitrilotriacetic acids has been performed. In comparison with iminodiacetic acid, the studied ligand has formed stronger complexes with alkaline earth metal ions and weaker complexes with transition metal ions; its complexes with the investigated cations have been weaker than these of nitrilotriacetic acid

Solvation State and Selective Solvation of D-Sorbitol in Water-Dimethylformamide Medium of Varying Composition

The solvation state of D-sorbitol has been determined in water-dimethylformamide (DMF) system (from 0 to 10 m.p.) using the method of polarimetry. The composition and formation constants of D-sorbitol – water – DMF heterosolvates have been obtained. The molar parts of D-sorbitol in heterosolvates have been found. It has been revealed that DMF acts as a selective solvent when its content is minimum (not higher than 0.7 m.p.), which is consistent with its higher nucleophilicity compared to water. If DMF concentration is higher than 0.7 m.p., there is inversion in solvation selectivity with water becoming a selective solvent. Under the experimental conditions, 12 water molecules in hydration shells were substituted with 6 DMF molecules. The substitution sequence of water molecules has been suggested