Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Shimojo, Kojiro; Fujiwara, Iori*; Saito, Takumi*; Oshima, Tatsuya*
Analytical Sciences, 40(8), p.1429 - 1436, 2024/08
Extraction ability of -dioctylthiodiglycolamic acid (T-DODGAA), a soft-base sulfur donor ligand with an amide group and a carboxylic acid connected by a thioether chain, for 56 metal ions have been comprehensively investigated and compared with that of N,N-dioctyldiglycolamic acid (DODGAA) with an etheric oxygen atom, a hard-base donor. The p of the thiodiglycolamic acid framework was determined to be 3.71 0.06 in water (0.1 M LiCl, 25C ) by potentiometric titration, indicating that T-DODGAA is a slightly weaker acid than DODGAA (p = 3.54 0.03). T-DODGAA can quantitatively extract various metal ions from the 56 metal ions through a proton-exchange reaction. T-DODGAA provided higher extraction performance than DODGAA for Hf(IV), Cr(III), Fe(III), Ni(II), Cu(II), Pd(II), Ag(I), Au(III), Hg(II), Al(III), and Ga(III), especially for soft metal ions. Furthermore, to demonstrate the practical feasibility of T-DODGAA for hydrometallurgy and metal recycling, we performed selective separation tests of rare metal ions such as Sc(III), Ni(II), Co(II), Pd(II), Au(III), In(III), and Ga(II) in metal-mixed extraction systems.
Shimojo, Kojiro; Fujiwara, Iori*; Oshima, Tatsuya*; Yokoyama, Keiichi; Yaita, Tsuyoshi
Analytical Sciences, 38(7), p.1003 - 1006, 2022/07
Times Cited Count:0 Percentile:0.00(Chemistry, Analytical)Liquid-liquid extraction of lanthanide (Ln) ions was investigated using -dioctylthiodiglycolamic acid (DOTDGAA), which is a sulfur donor ligand with an amide group and a carboxyl group connected by a thioether chain. The extraction performance and selectivity of DOTDGAA for Ln ions were compared with those of -dioctyldiglycolamic acid (DODGAA), which is also an oxygen donor ligand with a similar chemical structure, to assess the effect of the soft/hard donor atom on Ln separation. DOTDGAA quantitatively extracted all Ln ions while being selective toward light and middle Ln ions, in contrast to the selectivity of DODGAA for heavier Ln ions. Slope analysis demonstrated that the Ln transfer using DOTDGAA proceeded through a proton-exchange reaction, forming a 1:3 complex, Ln(DOTDGAA). The back-extraction of Ln ions from the extracting phase was successfully achieved under acidic conditions.
Sugita, Tsuyoshi; Fujiwara, Iori*; Okamura, Hiroyuki; Oshima, Tatsuya*; Baba, Yoshinari*; Naganawa, Hirochika; Shimojo, Kojiro
Solvent Extraction Research and Development, Japan, 24(2), p.61 - 69, 2017/05
We investigated an influence of amide group in diglycolamic acid-type extractants on extraction property of metal ions. The extraction characteristics of -dodecyldiglycolamic acid (CDGAA), with a secondary amide group, for 56 metal ions have been investigated, and compared with those of -dioctyldiglycolamic acid (DODGAA) with a tertiary amide group. Compared with DODGAA, CDGAA has a poor extraction performance and separation ability for rare-earth metal ions, except for Sc(III). However, CDGAA tended to provide better extraction for relatively small-sized metal ions than DODGAA. In addition, it was found that CDGAA enables the selective removal of Hg(II) from aqueous solutions containing various divalent metal ions.
Shimojo, Kojiro; Fujiwara, Iori*; Fujisawa, Kiyoshi*; Okamura, Hiroyuki; Sugita, Tsuyoshi; Oshima, Tatsuya*; Baba, Yoshinari*; Naganawa, Hirochika
Solvent Extraction Research and Development, Japan, 23(2), p.151 - 159, 2016/05
Liquid-liquid extraction of rare-earth (RE) cations has been investigated using -dodecyldiglycolamic acid (CDGAA) with a secondary amide group, and compared with that using -dioctyldiglycolamic acid (DODGAA) with a tertiary amide group. CDGAA enables quantitative transfer of all RE cations from moderately acidic solution, while being selective toward the heavier RE cations, and performs better than typical carboxylic-acid-type extractants. However, CDGAA provides low extraction performance and separation ability for RE cations compared with DODGAA because of the weaker basicity of the amide oxygen. Slope analysis demonstrated that RE transfer with CDGAA proceeded through a proton-exchange reaction, forming a 1:3 complex, RE(CDGAA). Structural characterization by X-ray diffraction revealed that three -butyldiglycolamic acid (CDGAA) molecules coordinated to the La central ion in a tridentate fashion and the La primary coordination sphere consisted of three oxygen atoms from the amide group, three oxygen atoms from the ether group, and three oxygen atoms from the carboxy group.
Fujiwara, Iori; Oshima, Tatsuya*; Baba, Yoshinari*; Naganawa, Hirochika
no journal, ,
no abstracts in English
Shimojo, Kojiro; Fujiwara, Iori*; Sugita, Tsuyoshi; Ueda, Yuki; Okamura, Hiroyuki; Oshima, Tatsuya*; Baba, Yoshinari*; Naganawa, Hirochika
no journal, ,
We have synthesized a thiodiglycolamic acid type ligand with a soft donor atom as a novel extractant. Extraction behavior of 56 metal ions using this extractant was comprehensively investigated. By comparing the extraction properties of this extractant with those of a diglycolamic acid type ligand with a hard donor atom, the effect of soft-hard property in the ether-site on extraction characteristics was clarified.
Sugita, Tsuyoshi; Fujiwara, Iori*; Okamura, Hiroyuki; Oshima, Tatsuya*; Baba, Yoshinari*; Naganawa, Hirochika; Shimojo, Kojiro
no journal, ,
The extractant plays a key role in solvent extraction. Previous studies reveal that acidic extractant with tridentate structure, DGAA, has superior extraction performance for various metal ions. in this study, to investigate a effect of each functional group in DGAA-type extractant, we carried out are synthesis and evaluation of analogous extractants of DGAA. In the result, the secondary amide-type DGAA tended to provide better extraction for relatively small-sized metal ions than tertiary amide-type DGAA, and the thioether chain-type DGAA showed superior extraction ability for soft metal ions compared to ether chain-type DGAA.
Fujiwara, Iori; Yabe, Makoto; Okamura, Hiroyuki; Oshima, Tatsuya*; Baba, Yoshinari*; Naganawa, Hirochika; Shimojo, Kojiro
no journal, ,
no abstracts in English
Yabe, Makoto; Fujiwara, Iori; Okamura, Hiroyuki; Sairenji, Shiho; Ohashi, Akira*; Naganawa, Hirochika; Shimojo, Kojiro
no journal, ,
no abstracts in English
Shimojo, Kojiro; Fujiwara, Iori*; Okamura, Hiroyuki; Oshima, Tatsuya*; Baba, Yoshinari*; Naganawa, Hirochika
no journal, ,
The extractant plays a key role in the extraction efficiency and the separation operation. Thus, the development of novel extractants, which perform better than conventional commercial extractants, is required for effective separation of metal ions. In this study, we have developed diglycolamic acid (DGAA) ligand as a new extractant. Extraction behavior of 56 metal ions using DGAA extractants was comprehensively investigated, and basic data on the extraction performance and selectivity of DGAA extractants was collected. In addition, we demonstrated the relationship between substituent group and extraction separation performance of DGAA extractants by the difference in performance of tertiary amide and secondary amide.