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Journal Articles

Synergistic enhancement of the extraction and separation efficiencies of lanthanoid(III) ions by the formation of charged adducts in an ionic liquid

Okamura, Hiroyuki; Mizuno, Masayoshi*; Hirayama, Naoki*; Shimojo, Kojiro; Naganawa, Hirochika; Imura, Hisanori*

Industrial & Engineering Chemistry Research, 59(1), p.329 - 340, 2020/01

 Times Cited Count:6 Percentile:64.04(Engineering, Chemical)

The synergistic ionic-liquid extraction and extraction equilibrium of lanthanoid(III) (Ln(III)) ions have been investigated using 2-thenoyltrifluoroacetone (Htta) and trioctylphosphine oxide (TOPO) in the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C$$_{4}$$mim][Tf$$_{2}$$N]). The selective synergistic effect for heavier Ln(III) ions was found using a combination of Htta and TOPO in [C$$_{4}$$mim][Tf$$_{2}$$N], leading to enhanced separability among Ln(III) ions. The extracted Ln(III) species and the extraction constants in the Htta-TOPO system were determined by three-dimensional extraction equilibrium analysis. The selective synergism for heavier Ln(III) ions in the Htta-TOPO system was ascribed to the formation of hydrophobic, charged adducts, such as Ln(tta)$$_{2}$$(TOPO)$$_{3}$$$$^{+}$$ and Ln(tta)(TOPO)$$_{3}$$$$^{2+}$$, in [C$$_{4}$$mim][Tf$$_{2}$$N].

Journal Articles

Synergistic extraction equilibrium of lanthanide(III) Ions with benzoylacetone and a neutral ligand in an ionic liquid

Hatakeyama, Mizuki*; Nishiyama, Yoshio*; Nagatani, Hirohisa*; Okamura, Hiroyuki; Imura, Hisanori*

Solvent Extraction Research and Development, Japan, 25(2), p.79 - 89, 2018/00

 Times Cited Count:9 Percentile:46.82(Chemistry, Multidisciplinary)

The synergistic extraction of trivalent lanthanide ions (Ln(III)) with benzoylacetone (Hba) and trioctyphosphine oxide (TOPO) in an ionic liquid (IL), 1-butyl-3-methyl-imidazolium bis(trifluoromethanesulfonyl)imide ([Bmim][Tf$$_{2}$$N]), has been investigated. The extractability of Ln(III) with Hba was significantly enhanced in the presence of TOPO. The composition and extraction constants of the extracted species for each Ln(III) were determined by 3-dimensional equilibrium analysis. It was found that all Ln(III) were extracted as cationic ternary complexes such as Ln(ba)$$_{2}$$(TOPO)$$_{2}$$$$^{+}$$ or Ln(ba)(TOPO)$$_{4}$$$$^{2+}$$ with Hba and TOPO. Furthermore, the formation constants of the cationic ternary complexes in the IL indicate that Lu(ba)(TOPO)$$_{4}$$$$^{2+}$$ is the most stable complex in the IL.

Journal Articles

Role of Tf$$_{2}$$N$$^{-}$$ anions in the ionic liquid-water distribution of europium(III) chelates

Okamura, Hiroyuki; Aoyagi, Noboru; Shimojo, Kojiro; Naganawa, Hirochika; Imura, Hisanori*

RSC Advances (Internet), 7(13), p.7610 - 7618, 2017/01

 Times Cited Count:14 Percentile:55.9(Chemistry, Multidisciplinary)

The role of bis(trifluoromethanesulfonyl)imide (Tf$$_{2}$$N$$^{-}$$) anions in the ionic liquid-water distribution systems of the Eu(III) chelates with 2-thenoyltrifluoroacetone (Htta) was investigated by the liquid-liquid distribution and time-resolved laser-induced fluorescence spectroscopy (TRLFS). The effect of the ionic liquids on the distribution constant of Eu(tta)$$_{3}$$ was evaluated by the regular solution theory. The distribution constant of Eu(tta)$$_{3}$$ in 1-alkyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C$$_{n}$$mim][Tf$$_{2}$$N]) was increased dramatically by the solvation effects of Eu(tta)$$_{3}$$ in [C$$_{n}$$mim][Tf$$_{2}$$N]. TRLFS for [Eu(tta)$$_{3}$$(H$$_{2}$$O)$$_{3}$$] synthesized revealed that the Eu(tta)$$_{3}$$ chelate was almost completely dehydrated in a series of [C$$_{n}$$mim][Tf$$_{2}$$N]. The Eu(tta)$$_{3}$$ chelate exists as di- or tri-hydrates in 1-ethyl-3-methylimidazolium perchlorate ([C$$_{2}$$mim][ClO$$_{4}$$]) containing 20 M water, whereas mono-hydrated chelate was formed in [C$$_{2}$$mim][Tf$$_{2}$$N, ClO$$_{4}$$] in the presence of 0.50 M Tf$$_{2}$$N$$^{-}$$ and 20 M water. These results show that the coordinated water molecules of [Eu(tta)$$_{3}$$(H$$_{2}$$O)$$_{3}$$] were replaced by the Tf$$_{2}$$N$$^{-}$$ anions. In fact, an anionic adduct, [Eu(tta)$$_{3}$$(Tf$$_{2}$$N)]$$^{-}$$, was observed by electrospray ionization mass spectrometry in the presence of [C$$_{4}$$mim][Tf$$_{2}$$N].

Journal Articles

Intramolecular cooperative effect of a macrocyclic receptor bearing $$beta$$-diketone fragments on the extraction of strontium into an ionic liquid

Okamura, Hiroyuki; Naganawa, Hirochika; Imura, Hisanori*; Shimojo, Kojiro

Proceedings of 20th International Solvent Extraction Conference (ISEC 2014), p.1046 - 1051, 2014/09

Journal Articles

Highly selective synergism for the extraction of lanthanoid(III) ions with $$beta$$-diketones and trioctylphosphine oxide in an ionic liquid

Okamura, Hiroyuki; Takagi, Hitomi*; Isomura, Taku*; Morita, Kotaro*; Nagatani, Hirohisa*; Imura, Hisanori*

Analytical Sciences, 30(3), p.323 - 325, 2014/03

 Times Cited Count:26 Percentile:73.92(Chemistry, Analytical)

Journal Articles

Specific cooperative effect of a macrocyclic receptor for metal ion transfer into an ionic liquid

Okamura, Hiroyuki; Ikeda, Atsushi*; Saito, Takumi*; Aoyagi, Noboru; Naganawa, Hirochika; Hirayama, Naoki*; Umetani, Shigeo*; Imura, Hisanori*; Shimojo, Kojiro

Analytical Chemistry, 84(21), p.9332 - 9339, 2012/11

 Times Cited Count:23 Percentile:67.6(Chemistry, Analytical)

Journal Articles

Measurement of fluorine distribution in carious enamel around 1.5-year aged fluoride-containing materials

Komatsu, Hisanori*; Kojima, Kentaro*; Funato, Yoshiki*; Matsuda, Yasuhiro*; Kijimura, Taiki*; Okuyama, Katsushi*; Yamamoto, Hiroko*; Iwami, Yukiteru*; Ebisu, Shigeyuki*; Nomachi, Masaharu*; et al.

JAEA-Review 2011-043, JAEA Takasaki Annual Report 2010, P. 85, 2012/01

Journal Articles

Laser-induced fluorescence and infrared spectroscopic studies on the specific solvation of tris(1-(2-thienyl)-4,4,4-trifluoro-1,3-butanedionato)europium(III) in an ionic liquid

Okamura, Hiroyuki; Sakae, Hiroki*; Kidani, Keiji*; Hirayama, Naoki*; Aoyagi, Noboru; Saito, Takumi*; Shimojo, Kojiro; Naganawa, Hirochika; Imura, Hisanori*

Polyhedron, 31(1), p.748 - 753, 2012/01

 Times Cited Count:24 Percentile:86.45(Chemistry, Inorganic & Nuclear)

Journal Articles

Fluorine analysis of human enamel around fluoride-containing materials under different pH-cycling by $$mu$$-PIGE/PIXE system

Komatsu, Hisanori*; Yamamoto, Hiroko*; Matsuda, Yasuhiro*; Kijimura, Taiki*; Kinugawa, Michihiko*; Okuyama, Katsushi*; Nomachi, Masaharu*; Yasuda, Keisuke*; Sato, Takahiro; Oikawa, Masakazu*

Nuclear Instruments and Methods in Physics Research B, 269(20), p.2274 - 2277, 2011/10

 Times Cited Count:16 Percentile:80(Instruments & Instrumentation)

Journal Articles

Synergistic effect of 18-crown-6 derivatives on chelate extraction of lanthanoids(III) into an ionic liquid with 2-thenoyltrifluoroacetone

Okamura, Hiroyuki; Hirayama, Naoki*; Morita, Kotaro*; Shimojo, Kojiro; Naganawa, Hirochika; Imura, Hisanori*

Analytical Sciences, 26(5), p.607 - 611, 2010/05

 Times Cited Count:48 Percentile:84.67(Chemistry, Analytical)

Journal Articles

Cooperative intramolecular interaction of diazacrown ether bearing $$beta$$-diketone fragments on an ionic liquid extraction system

Shimojo, Kojiro; Okamura, Hiroyuki; Hirayama, Naoki*; Umetani, Shigeo*; Imura, Hisanori*; Naganawa, Hirochika

Dalton Transactions, 2009(25), p.4850 - 4852, 2009/07

A novel extractant $$beta$$-diketone-substituted diaza-18-crown-6 demonstrated very efficient extraction of Sr$$^{2+}$$ due to an intramolecular synergistic effect on the ionic liquid extraction system and recovery of Sr$$^{2+}$$ from the ionic liquid was successfully achieved under acidic conditions.

Journal Articles

EUV light source by high power laser

Izawa, Yasukazu*; Nishihara, Katsunobu*; Tanuma, Hajime*; Sasaki, Akira; Murakami, Masakatsu*; Sunahara, Atsushi*; Nishimura, Hiroaki*; Fujioka, Shinsuke*; Aota, Tatsuya*; Shimada, Yoshinori*; et al.

Journal of Physics; Conference Series, 112, p.042047_1 - 042047_4, 2008/00

 Times Cited Count:7 Percentile:93.09

In the development of a high power EUV source used in the EUV lithography system, we have been constructed EUV database of laser-produced tin plasma by the theoretical and experimental studies. On the basis of our understanding, the optimum conditions of lasers and plasmas were clarified, and we proposed the guidelines of laser plasma to obtain clean, efficient and high power EUV source for the practical EUV lithography system. In parallel to such studies, novel targets and high power laser system to generate the optimized EUV source plasma have been developed.

Journal Articles

Solvent effect in supercritical carbon dioxide extraction of metal ions

Meguro, Yoshihiro; Ogiyanagi, Jin*; Tomioka, Osamu; Imura, Hisanori*; Ohashi, Kozaburo*; Yoshida, Zenko; Nakashima, Mikio

Proceedings of 2nd International Symposium on Supercritical Fluid Technology for Energy and Environment Applications (Super Green 2003), p.175 - 179, 2004/00

One of the most attractive properties of SFE is that changing solvent properties by tuning pressure can control distribution behavior of a metal ion. Distribution ratio (D) of uranium(VI) and plutonium(IV) with tributyl phosphate (TBP) from a nitric acid solution and palladium(II) with 2-methyl-8-qunolinol (HMQ) from a hydrochloric solution were determined in SFE at various pressures. In the extraction system using TBP, a linear relationship between the logarithmic distribution ratio (log D) and the solubility parameter of CO$$_{2}$$ was observed. The solubility parameter is difined based on the regular solution theory and is one of the parameters depending on the pressure. On the other hand, a linear relationship with a positive slope between log D and the solubility parameter was observed in the extraction system using HMQ. Most of the extractant was dissolved in the aqueous phase as H$$_{2}$$MQ$$^{+}$$ under the extraction condition examined.

Oral presentation

Ionic liquid synergy extraction of lanthanides with beta-diketone and crown ether

Okamura, Hiroyuki; Hirayama, Naoki*; Shimojo, Kojiro; Naganawa, Hirochika; Imura, Hisanori*

no journal, , 

no abstracts in English

Oral presentation

Synergy extraction of lanthanides using macrocyclic compounds into ionic liquids

Okamura, Hiroyuki; Hirayama, Naoki*; Shimojo, Kojiro; Naganawa, Hirochika; Imura, Hisanori*

no journal, , 

no abstracts in English

Oral presentation

Intramolecular synergistic effect in ionic liquid extraction system of metal ions

Okamura, Hiroyuki; Shimojo, Kojiro; Hirayama, Naoki*; Umetani, Shigeo*; Imura, Hisanori*; Naganawa, Hirochika

no journal, , 

no abstracts in English

Oral presentation

Intramolecular synergistic extraction using crown ether bearing b-diketone fragments in an ionc liquid

Okamura, Hiroyuki; Shimojo, Kojiro; Hirayama, Naoki*; Umetani, Shigeo*; Imura, Hisanori*; Naganawa, Hirochika

no journal, , 

no abstracts in English

Oral presentation

Intramolecular synergy effect of crown ether bearing b-diketone fragments and development of ionic liquids extraction system

Shimojo, Kojiro; Okamura, Hiroyuki; Hirayama, Naoki*; Umetani, Shigeo*; Imura, Hisanori*; Naganawa, Hirochika

no journal, , 

no abstracts in English

Oral presentation

Analysis of extraction equilibria in ionic liquid synergistic extraction systems using crown ethers

Okamura, Hiroyuki; Hirayama, Naoki*; Shimojo, Kojiro; Naganawa, Hirochika; Imura, Hisanori*

no journal, , 

no abstracts in English

Oral presentation

Intramolecular synergistic effect on an ionic liquid extraction system using crown ether bearing $$beta$$-diketone fragments

Okamura, Hiroyuki; Shimojo, Kojiro; Hirayama, Naoki*; Umetani, Shigeo*; Imura, Hisanori*; Naganawa, Hirochika

no journal, , 

no abstracts in English

45 (Records 1-20 displayed on this page)