Preparation of Iron(II) by Electrolytic Reduction and Extraction with 4, 4, 4-Trifluoro-1-(2-thienyl)-1, 3-butanedione into Various Organic Solvents

抄録

Previous to the extraction, preparation of a solution containing a quantitative amount of Fe²⁺ was performed by electrolytic reduction of Fe³⁺ at a potential of 0.1V vs. Ag/AgCl reference electrode. Solvent extraction of iron(II) was carried out using 4, 4, 4-trifluoro-1-(2-thienyl)-1, 3-butanedione (2-thenoyltrifluoroacetone, Htta) into various organic solvents: heptane, benzene, 4-methyl-2-pentanone, pentyl acetate, 1-hexanol and 1-heptanol. In order to avoid the oxidation of iron(II), the organic and aqueous phases were bubbled with nitrogen gas before extraction; the iron(II) solution was also handled in a nitrogen-filled glove box. For every solvent except 1-heptanol, almost all the extracted species was Fe^III(tta)₃. Analysis of the extraction equilibrium and UV-visible spectra of the organic phase showed that iron was extracted as Fe^II(tta)₂ by using 1-heptanol. In this extraction system, the extraction constant was 10^-3.45.