Solvent extraction of various metals including actinides by bidentate and tridentate diamides

2座,3座配位活性ジアミドによる、アクチノイドを含む多様な金属の溶媒抽出

佐々木 祐二  ; 木村 貴海 ; 小熊 幸一*

Sasaki, Yuji; Kimura, Takaumi; Oguma, Koichi*

多様なジアミド化合物を合成し、アクチノイドイオン(An(III), (IV), (V)、及び(VI))抽出のために利用した。3座配位子として働くジグリコールアミド(DGA)化合物は非常に高いAn抽出特性を示した。疎水性を高めるため、より長いアルキル基を修飾したDGA化合物を合成し抽出性能を調べた。その結果、TODGA(tetraoctyl-diglycolamide),TDDGA(tetradecyl-diglycolamide)は無極性溶媒に高い溶解度を示す一方で水中にほとんど溶解しない。TODGAを用いたさまざまな金属の溶媒抽出結果は、イオン半径90120pmの2, 3, 4価金属に高い分配比を示した。幾つか置換基を交換した化合物の特性を調べた結果に基づき、優れた抽出性能を示すDGA化合物を提案する。

Many diamide-type extractants were synthesized and tested for the extraction of actinides (III), (IV), (V) and (VI). The diglycolamides (DGA) with two amidic oxygen and one ether oxygen, which show the tridentate feature, have the high extractability of actinides (An). In order to increase the lipophilic property, the diglycolamides with the different functional groups attached to N atoms were synthesized and examined for their extractability. It was found that tetraoctyl-diglycolamide (TODGA) and tetradecyl-diglycolamide (TDDGA) exhibit the satisfactory dissolution into dodecane with less solubility in HO. The results of various metal extractions using TODGA revealed that the divalent, trivalent and tetravalent metals with ionic radius of 90-120 pm gave notably high D values. After elucidation of the effect on substitution of the functional group, the chemical form of DGA to have high performance on An extraction was proposed.