Novel Mechanisms of Synergism and Coextraction caused by Metal Chelates as Complex Ligand

1.2- thenoyltrifluoro丙酮（Htta）萃取镧系元素（III） （Ln），特别是La^<3+>，同时萃取出Al^<3+>、Sc^<3+>和Fe^<3+>等金属离子，这些金属离子容易被萃取到有机相；这就是共萃取的发现。从平衡和红外光谱研究中发现，共萃取归因于Ln(tta)_3与M(tta)_3在有机相中形成1:1加合物或双核配合物。在乙酰丙酮（Hacae）体系。Cu^<2+>和Zr^<4+>导致了Ln的共萃取，这也是由于双核配合物的形成。Co(acae)_3和Co(tta)_3的加入对Sr^<2+>和Ba^<2+>等碱土金属（II） （AE）的萃取有协同增强作用。增效作用是由于与Co螯合物形成了AR(tta)_2的双核配合物。此外，当Al^<3+>或Fe^<3+>以M8TTA)_3的形式萃取到有机相中时，hta对Sr^<2+>的萃取作用增强。这种现象是AE与AL^<3+>或Fe^<3+>.3的共同萃取。研究了4-异丙基邻苯二酮（Hipt）与稀土金属（III） （RE）的共萃取。Co(ipt)_3是hta萃取稀土的有效配合体，但对稀土的萃取效果没有影响。另一方面，LA^<3+>的提取率（分布比）在3 × 10^<-5> M Sc^<3+>、Y^<3+>和Lu^<3+>时分别提高了60、80和200倍。由于已知稀土二聚体在Hipt体系中被萃取，因此本研究中发现的共萃取可归因于稀土的异双核配合物的形成。

1.Extraction of lanthanide(III) (Ln), especially La^<3+>, with 2-thenoyltrifluoroacetone (Htta) was remarkably enhanced along with the extraction of metal ions such as Al^<3+>, Sc^<3+>, and Fe^<3+> which are readily extracted to the organic phase; that is the coextraction was found out. From the equilibrium and IR studies, the coextraction was found to be ascribed to the formation of a 1:1 adduct or binuclear complex of Ln(tta)_3 with M(tta)_3 in the organic phase. In the acetylacetone (Hacae) system. Cu^<2+> and Zr^<4+> caused the coextraction of Ln, which was also due to the formation of binuclear complexes.2.Synergistic enhancement of the extraction of alkaline earth metals(II) (AE) such as Sr^<2+> and Ba^<2+> with Htta was found by the addition of Co(acae)_3 and CO(tta)_3. The synergism was ascribed to the formation of a binuclear complex of AR(tta)_2 with the Co chelates. Furthermore, the extraction of Sr^<2+> with Htta was enhanced when Al^<3+> or Fe^<3+> was extracted into the organic phase as M8TTA)_3. This phenomenon is the coextraction of AE along with the extraction of AL^<3+> or Fe^<3+>.3.The coextraction of rare earth metals(III) (RE) with 4-isopropyltropolone (Hipt) has been studied. The extraction of RE was not affected by the addition of Co(ipt)_3 although it acted as an effective complex ligand in the extraction of RE with Htta. On the other hand the extraction (distribution ratio) of LA^<3+> was increased by a factor of 60,80, and 200 with the extraction of 3x 10^<-5> M Sc^<3+>, Y^<3+>, and Lu^<3+>, respectively. Since the RE-dimers are known the be extracted in the Hipt system, the coextraction found in this study can be ascribed to the formation of hetero-binuclear complexes of RE.