title: Liquid-liquid extraction of divalent transition metal ions with a novel bis-β-ketoester extraction reagent.
abstract: Solvent extraction is a very effective method for the separation of metal ions. N,N'-bis(2-hydroxy-phenylmethyl)-N,N'-bis(2-pyridylmetyl)-1,2-ethanediamine derivatives have been researched for solvent extraction of metal ions. In this study. We synthesized a bis-β-ketoester ligand and evaluated its selectivity in extracting divalent transition metal ions. The ligand, hexane-1,6-diyl bis (4,4,4-trifluoro-3-oxobutanoate) (H2hdfob or H2L) was synthesized in one step by transesterification of ethyl 4,4,4-trifluoroacetoacetate with 1,6-hexanediol. The multidentate ligand H2hdfob successfully extracted divalent transition metal ions into its organic phase. The relationship between logD, which is a distribution ratio (D), and pH or log[H2L]o exhibited linear relationships with slopes of approximately +2 and +1, respectively. Based on these results, we proposed a mechanism of extraction with H2hdfob. Extraction with tetradentate H2hdfob provides a new method for enhancing selectivity of divalent metal ions, in comparison to other bidentate ligands.
authors: Tokyo Gakugei University, Nukuikitamachi 4-1-1, Koganei, Tokyo 184-8501, Japan. Electronic address: m121809m@st.u-gakugei.ac.jp.
authors: Satoshi
authors: S
authors: Ohmuro
authors: Tokyo Gakugei University, Nukuikitamachi 4-1-1, Koganei, Tokyo 184-8501, Japan.
authors: Hiromasa
authors: H
authors: Kishi
authors: Tokyo Gakugei University, Nukuikitamachi 4-1-1, Koganei, Tokyo 184-8501, Japan.
authors: Nobutoshi
authors: N
authors: Yoshihara
authors: Tokyo Gakugei University, Nukuikitamachi 4-1-1, Koganei, Tokyo 184-8501, Japan.
authors: Hisao
authors: H
authors: Kokusen
keywords: Bis-β-ketoester; Divalent transition metal ions; Extraction mechanism; Liquid–liquid extraction