31P, 17O,13C, and 1H NMR Studies of the Structure of Bismuth Di-2-ethylhexylphosphates
Статья (Full article),
Russian Journal of Inorganic Chemistry
, E-ISSN: 1531-8613
Boreskov Institute of Catalysis, Siberian Division, Russian Academy of Sciences, pr. Akademika Lavrent'eva 5, Novosibirsk, 630090, Russian Federation
Inst. Solid-State Chem. Mineral P., Siberian Division, Russian Academy of Sciences, ul. Kutateladze 18, Novosibirsk, 630128, Russian Federation
Extraction of bismuth(III) from perchloric acid solutions with a solution of di-(2-ethylhexyl)phosphoric acid (D2EHPA) in hexane or carbon tetrachloride is studied by 31P, 17O,13C, and 1H NMR. The extracted complexes are characterized. The behavior of the extracting agent in the given system in a wide range of pH is studied. When bismuth is extracted with D2EHPA from concentrated perchloric acid solutions, the latter transfers into the organic phase as two species - the monohydrate HClO4 · H2O and the solvate HClO4 · nHR. The solvate is an active in extraction of Bi as the perchlorate-containing dialkylphosphate BiClO4R2. From moderately acid solutions, bismuth is extracted as the acid solvated complex BiR3 · SHR at the D2EHPA : Bi ratio (n) ≥ 8. A decrease in this ratio leads to the appearance of 31P NMR signals of the bismuth dialkylphosphate with a polymeric structure. The fraction of this complex increases with a decrease in n to 2.6. In extraction from solutions with pH 1-2 and at n close to unity, the extracted form is oxohydroxodialkylphosphate Bi6O4(OH)4R6.