Linear 2-Ethylhexyl Imidophosphoric Esters as Effective Rare-Earth Element Extractants.

Autor: Bredov, Nikolay S., Gorlov, Mikhail V., Esin, Andrey S., Bykovskaya, Anna A., Kireev, Vyacheslav V., Sinegribova, Oksana A., Ryabochenko, Maria D.
Předmět:
Zdroj: Applied Sciences (2076-3417); Feb2020, Vol. 10 Issue 4, p1229, 15p
Abstrakt: Imidophosphoric organic esters containing phosphoryl groups are potential polydentate ligands and promising extractants of rare-earth elements. For their preparation, a monophosphazene salt [PCl3=N−PCl3]+[PCl6] and short phosphazene oligomers of the general formula [Cl–(PCl2=N)n–PCl3]+[PCl6], where n = 4–7, were synthesized via living cationic polymerization of Cl3P=NSiMe3 and used as starting compounds. All phosphazenes were reacted with 2-ethylhexanol to obtain the corresponding esters of imidophosphoric acids (EIPAs). The formation of imidophosphoric acids occurs due to the phosphazene-phosphazane rearrangement of –P(OR)2=N– or –P(OH)(OR)=N– units, where R = 2-ethylhexyl. The prepared EIPAs were characterized by 1H, 31P NMR, and MALDI-TOF analyses and their extractive capacity towards lanthanide ions in aqueous solutions of nitric acid was examined. The EIPAs are mixtures of mono-, di-, and trifunctional compounds of the type HxA, where x = 1–3, which can form chelate complexes of lanthanide ions [Ln(A)z], where z = 3–6, depending on the chain length. The longer chain EIPAs are more suitable for collective rare-earth elements extraction. A comparison of the extraction properties of the EIPAs with the industrially used polyalkylphosphonitrilic acid (PAPNA) was drawn. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index