PREPARATION OF IRON(II) BY ELECTROLYTIC REDUCTION AND EXTRACTION WITH4,4,4-TRIFLUORO-1-(2-THIENYL)-1,3-BUTANEDIONE INTO VARIOUS ORGANIC-SOLVENTS

Previous to the extraction, preparation of a solution containing a qua ntitative amount of Fe2+ was performed by electrolytic reduction of Fe 3+ at a potential of 0.1 V vs. Ag/AgCl reference electrode. Solvent ex traction of iron(II) was carried out using 4,4,4-trifluoro-1-(2-thieny l)-1,3-butanedione (2-thenoyltrifluoroacetone, Htta) into various orga nic 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-fille d glove box. For every solvent except 1-heptanol, almost all the extra cted species was Fe(III)(tta)3. Analysis of the extraction equilibrium and UV-visible spectra of the organic phase showed that iron was extr acted as Fe(II)(tta)2 by using 1-heptanol. In this extraction system, the extraction constant was 10(-3.45).