Studies on the extraction of soft acid metal species using MIDOA and analogous compounds

MIDOAと関連化合物を使ったソフト金属の抽出に関する研究

佐々木 祐二  ; 佐伯 盛久; 須郷 由美; 池田 泰久*; 川崎 武志*; 鈴木 智也*; 大橋 朗*

Sasaki, Yuji; Saeki, Morihisa; Sugo, Yumi; Ikeda, Yasuhisa*; Kawasaki, Takeshi*; Suzuki, Tomoya*; Ohashi, Akira*

新抽出剤のMIDOA(メチルイミノジオクチルアセトアミド)を用いて、Pd(II), Nb(V), Ta(V), Cr(VI), Mo(VI), W(VI), Tc(VII), Re(VII)等の溶媒抽出を行い、関連化合物のIDOA(イミノジオクチルアセトアミド)やMIDEHA(メチルイミノジエチルヘキシルアセトアミド)、TODGA(テトラオクチルジグリコールアミド)、TDGA(チアジグリコールアミド)等の結果を比較した。これらの結果より、MIDOAによる分配比はIDOAやMIDEHAよりやや高いこと、Pd, Re分配比はTODGA, TDGAより高いことを明らかにした。

An extractant, methylimino-bis--dioctylacetamide (MIDOA), was used for the extraction of soft acid metals. It was found that MIDOA can extract not only Cr(VI), Mo(VI), W(VI), Tc(VII) and Re(VII), whose metals can form the oxonium anions due to their high oxidation states, but also other metal cations, like Nb(V), Ta(V) and Pd(II). Analogous compounds, imino-bis--dioctylacetamide (IDOA) and methylimino-bis--di-2-ethylhexylacetamide (MIDEHA), are synthesized and compared for their extractability. It is clear that these extractants have almost same or lower values than those for MIDOA. In order to examine the effect on extractability with different donor atoms, TODGA (-tetraoctyl-diglycolamide) and TDGA (-tetraoctyl-tyiodiglycolamide) having oxygen and sulfur donor are employed. The comparison of their extractabilities suggests that the trend of Pd and Re extraction is N S O and N O S, respectively.