Comprehensive extraction study using an acidic diamide-type ligand with tetradentate structure

Shimojo, Kojiro   ; Sugita, Tsuyoshi   ; Yabe, Makoto*; Okamura, Hiroyuki   ; Ohashi, Akira*; Naganawa, Hirochika  

Solvent extraction is an effective method for the separation and purification of metal ions. In previous study, we developed dioctyldiglycolamic acid extractant (DODGAA) with an amide group and a carboxy group connected by an ether chain, and reported DODGAA performs better than commercial extractants. In this study, we have synthesized a novel acidic diamide-type extractant (TONTADA) with two amide groups and a carboxy group connected by a nitrogen donor atom and have comprehensively investigated the extraction of 56 metal ions. It was found that the novel extractant TONTADA provides excellent extraction performance and separation ability for various rare metal ions such as Sc(III), Cu(II), Ni(II), Co(II), In(III), Ga(III), Hg(II), platinum-group metal, Hf(IV), V(V), Mo, W(VI), and Re(VII) compared with conventional extractants and DODGAA.