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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 (C
DGAA), 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 (C
DGAA) 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.
Oshima, Tatsuya*; Baba, Yoshinari*; Shimojo, Kojiro; Goto, Masahiro*
Current Drug Discovery Technologies, 4(4), p.220 - 228, 2007/12
A macrocyclic calix[6]arene carboxylic acid derivative is found to extract lysine-rich protein cytochrome c from aqueous media into organic media through the complexation between the calixarene molecules and lysine residues on the surface of the protein. This article summarizes both the mechanism of protein extraction by the calixarene as well as the potential applications of the extraction process. The extraction process can be used for the purification of proteins through selective extraction and back-extraction under optimized conditions. On the other hand, the extracted protein exhibits enzymatic activity in organic media. The formation of a supramolecular complex by recognizing the residues on a protein surface can be construed as a novel recognition and/or modification method for biomacromolecules.
Fujiwara, Iori; Oshima, Tatsuya*; Baba, Yoshinari*; Naganawa, Hirochika
no journal, ,
no abstracts in English
Fujiwara, Iori; Yabe, Makoto; Okamura, Hiroyuki; Oshima, Tatsuya*; Baba, Yoshinari*; 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.
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.
