研究者詳細 - 神﨑　亮

論文 - 神﨑　亮

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Kanzaki R. . Acid-base property and pH of protic ionic liquids . Bunseki Kagaku64 ( 3 ) 189 - 196 2015年3月招待査読

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Bunseki Kagaku

A certain type of onium salt whose melting point is near an arbitrary temperature is a so-called a protic ionic liquid (PIL). PILs are expected to be the ‘third solvents’ that follow water and organic solvents for many techniques in analytical chemistry, such as separation, purification, and extraction, because of its ability for being an acid-base reaction medium. In this article, some ideas for understanding the acid-base reactions in PILs are briefly introduced with comparing with those in water and conventional non-aqueous solvents (i.e., organic solvents). Then, recent results of the autoprotolysis constants and acid dissociation constants in PILs are summarized to show quantitatively that PILs exhibit their acid-base property, depending on the constituting anion and cation. The relationship between the pH and the reactivity of hydrogen ion in a typical PIL, ethylammonium nitrate, is compared with that in water.

DOI： 10.2116/bunsekikagaku.64.189

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Tomiyasu T., Takenaka S., Noguchi Y., Kodamatani H., Matsuyamab A., Oki K., Kono Y., Kanzaki R., Akagi H. . Estimation of the residual total mercury in marine sediments of Minamata Bay after a pollution prevention project . Marine Chemistry159 19 - 24 2014年2月査読

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Marine Chemistry

To estimate the current contamination levels in Minamata Bay, the vertical and horizontal distributions of mercury in the sediment were investigated. Sediment core samples were collected in 2002, 2006, 2008, and 2010 at 12 locations by gravity core sampling in Minamata Bay and Fukuro Bay, which is located in the southern part of Minamata Bay. The average total mercury concentrations during each year in the surface sediment were 2.47-3.34 and 3.50-4.66mgkg-1 for Minamata Bay and Fukuro Bay, respectively; significant variation in the values was not observed during the study period. The total mercury concentration in Fukuro Bay increased with increasing depth and reached a maximum at 8-14cm from the surface and decreased with increasing depth in the deeper layer. In Minamata Bay, the total mercury concentration did not change significantly from the surface to a depth of 10cm and the values were considerably higher than the background level. In the lower layers of the long cores taken from both areas, the total mercury concentration decreased with depth, and the deepest layers exhibited relatively uniform low values. These values can be considered to represent the background concentration in the absence of anthropogenic influence. The depth of the sediment affected by the effluent was estimated to be 20±7cm and 33±4cm for Minamata Bay and Fukuro Bay, respectively. Furthermore, it was estimated from the average concentration and volume of the contaminated layer that approximately 1ton of discharged mercury remained in the sediment of the two bays. © 2014 Elsevier B.V.

DOI： 10.1016/j.marchem.2013.12.002

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Tatsuya Umecky, Toshiyuki Takamuku, Ryo Kanzaki, Masaya Takagi, Eiji Kawai, Tomoya Matsumoto, Toshitaka Funazukuri . Role of water in complexation of 1,4,7,10,13,16-hexaoxacyclooctadecane (18-crown-6) with Li+ and K+ in hydrophobic 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide ionic liquid . Journal of Inclusion Phenomena and Macrocyclic Chemistry80 ( 3-4 ) 401 - 407 2014年査読

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Inclusion Phenomena and Macrocyclic Chemistry

Complexation characteristics of 1,4,7,10,13,16-hexaoxacyclooctadecane (18-crown-6, 18C6) with Li+ and K+ in a hydrophobic ionic liquid of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide under dry and humid conditions at 298.2 K were studied by 1H and 13C NMR chemical shifts. The comparison of the 1H and 13C chemical shifts of 18C6 molecule between the dry and humid IL solutions without the alkali metal ions showed that uncomplexed 18C6 molecules are solvated by water molecules in the humid ionic liquid solution. The changes in the 1H and 13C chemical shifts of 18C6 ligand molecule with the increases in the Li+ and K+ concentrations revealed that in both dry and humid ionic liquid solutions 18C6 molecule forms 1:1 complexes with Li+ and K+. The 1H NMR data of water molecules in the humid ionic liquid solutions demonstrated that water molecules interact with Li+-18C6 complexes and free Li+, but do not with K+ -18C6 complexes and free K+. The mechanisms of the formation of the Li+ and K+ complexes in the humid ionic liquid solution are different from each other due to the differences in the complex-water interactions.

DOI： 10.1007/s10847-014-0427-1

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Doi H., Song X., Minofar B., Kanzaki R., Takamuku T., Umebayashi Y. . A new proton conductive liquid with no ions: Pseudo-protic ionic liquids . Chemistry - A European Journal19 ( 35 ) 11522 - 11526 2013年8月査読

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Chemistry - A European Journal

Liquids with no ions! Raman analysis and quantum calculations suggest that electrically neutral molecular species predominantly exist in an N-methylimidazole and acetic acid equimolar mixture, and that ionic species are rather minor. Nevertheless, the mixture has significant ionic conductivity, and shows "good ionic" or "superionic" behavior (see figure). It may be suitable to call such liquids "pseudo-ionic liquids" rather than "ionic liquids". Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

DOI： 10.1002/chem.201302228

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Kodamatani H., Matsuyama A., Saito K., Kono Y., Kanzaki R., Tomiyasu T. . Sensitive determination method for mercury ion, methyl-, ethyl-, and phenyl-mercury in water and biological samples using high-performance liquid chromatography with chemiluminescence detection . Analytical Sciences28 ( 10 ) 959 - 965 2012年10月査読

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Analytical Sciences

A sensitive determination method for mercury speciation analysis was developed. Four mercury species, mercury ion, methylmercury, ethylmercury, and phenylmercury, were complexed with emetine-dithiocarbamate (emetine-CS2), and then injected onto a HPLC instrument coupled with a tris(2,2'-bipyridine)ruthenium(III) chemiluminescence detection system. The emetine-CS2 complexing agent was effectively used to measure the concentration in addition to serving as a separation and detection reagent. The calibration curves for these mercury complexes were linear in the range of 0.050-10 μg L-1 (as Hg). The limit of detection for (emetine-CS2)2Hg, emetine-CS2-methylmercury, emetine-CS2-ethylmercury, and emetine-CS2-phenylmercury were 30, 17, 21, and 22 ng L-1, respectively. The sensitivity of this method enables the determination of mercury species in water samples at sub-ppb levels. Furthermore, the method was applied to biological samples in combination with acid leaching and liquid-liquid extraction using emetine-CS2 as an extraction reagent. The determination results were in good agreement with the values of the certified reference materials. © The Japan Society for Analytical Chemistry.

DOI： 10.2116/analsci.28.959

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Tomiyasu T., Hirose M., Kodamatani H., Anazawa K., Kanzaki R., Kono Y., Shiga Y. . The distribution of arsenic concentration around Gejiu tin mine, Yunnan, China . Bunseki Kagaku61 ( 1 ) 21 - 29 2012年1月査読

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Bunseki Kagaku

In order to estimate the dispersion of arsenic released thorough mining activity, a total of 39 soil samples were taken around the Gejiu tin mine, Yunnan, China. The highest total arsenic concentration, 1.1×104 mg kg-1, was observed in the tailing. Although the concentration in soil samples was slightly lower than that in the tailings, higher than 5.1×102 mg kg-1 of arsenic was still observed. A linear relation was observed between SiO2 and Fe2O3, which can be used for estimating the dispersion of the tailings. A trend was observed that the higher the chemical index of alteration, the lower the arsenic concentration, which suggests the elution of arsenic from tailings through weathering. © 2012 The Japan Society for Analytical Chemistry.

DOI： 10.2116/bunsekikagaku.61.21

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Ryo Kanzaki, Hiroyuki Doi, Xuedan Song, Shota Hara, Shin-ichi Ishiguro, Yasuhiro Umebayashi . Acid-Base Property of N-Methylimidazolium-Based Protic Ionic Liquids Depending on Anion . The Journal of Physical Chemistry B 116 14146 - 14152 2012年査読

Toshiyuki Takamuku, Hiroshi Wada, Chiemi Kawatoko, Takuya Shimomura, Ryo Kanzaki, Munetaka Takeuchi . Amide-induced phase separation of hexafluoroisopropanol-water mixtures depending on the hydrophobicity of amides . Physical Chemistry and Chemical Physics14 8335 - 8347 2012年査読

Xuedan SONG, Ryo KANZAKI, Shin-ichi ISHIGURO, Yasuhiro UMEBAYASHI . Physicochemical and Acid-base Properties of a Series of 2-Hydroxyethylammonium-based Protic Ionic Liquids . Analytical Sciences28 469 - 474 2012年査読

Xuedan Song, Hiroshi Hamano, Babak Minofar, Ryo Kanzaki, Kenta Fujii, Yasuo Kameda, Shinji Kohara, Masayoshi Watanabe, Shin-ichi Ishiguro, Yasuhiro Umebayashi . Structural Heterogeneity and Unique Distorted Hydrogen Bonding in Primary Ammonium Nitrate Ionic Liquids Studied by High-Energy X-ray Diffraction Experiments and MD Simulations . The Journal of Physical Chemistry B116 2801 - 2813 2012年査読

Fujii K., Kanzaki R., Takamuku T., Kameda Y., Kohara S., Kanakubo M., Shibayama M., Ishiguro S., Umebayashi Y. . Experimental evidences for molecular origin of low-Q peak in neutron X-ray scattering of 1-alkyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide ionic liquids . Journal of Chemical Physics135 ( 24 ) 244502 2011年12月査読

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Chemical Physics

Short- and long-range liquid structures of C nmImTFSA - with n 2, 4, 6, 8, 10, and 12 have been studied by high-energy x-ray diffraction (HEXRD) and small-angle neutron scattering (SANS) experiments with the aid of MD simulations. Observed x-ray structure factor, S(Q), for the ionic liquids with the alkyl-chain length n 6 exhibited a characteristic peak in the low-Q range of 0.2-0.4 -1, indicating the heterogeneity of their ionic liquids. SANS profiles I H(Q) and I D(Q) for the normal and the alkyl group deuterated ionic liquids, respectively, showed significant peaks for n 10 and 12 without no form factor component for large spherical or spheroidal aggregates like micelles in solution. The peaks for n 10 and 12 evidently disappeared in the difference SANS profiles I(Q) I D(Q) - I H(Q), although that for n 12 slightly remained. This suggests that the long-range correlations originated from the alkyl groups hardly contribute to the low-Q peak intensity in SANS. To reveal molecular origin of the low-Q peak, we introduce here a new function; x-ray structure factor intensity at a given Q as a function of r, S Qpeak(r). The S Qpeak(r) function suggests that the observed low-Q peak intensity depending on n is originated from liquid structures at two r-region of 5-8 and 8-15 for all ionic liquids examined except for n 12. Atomistic MD simulations are consistent with the HEXRD and SANS experiments, and then we discussed the relationship between both variations of low-Q peak and real-space structure with lengthening the alkyl group of the C nmIm. © 2011 American Institute of Physics.

DOI： 10.1063/1.3672097

Toshiyuki Takamuku, Takuya Shimomura, Mai Tachikawa, Ryo Kanzaki . N,N-Dimethylformamideinduced phase separation of hexafluoroisopropanol- water mixtures . Physical Chemistry and Chemical Physics13 11222 - 11232 2011年査読

Kodamatani H., Kanzaki R., Tomiyasu T., Saito K., Kono Y. . Determination of Organic and Inorganic Mercury Species as Emetine Dithiocarbamate Complexes by High-Performance Liquid Chromatography with Electrogenerated Tris(2,2′-bipyridine)ruthenium(III) Chemiluminescence Detection . Analytical Letters44 ( 17 ) 2769 - 2779 2011年査読

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Analytical Letters

A sensitive method for simultaneous determination of organic and inorganic mercury species has been developed and is presented in this study. The method is based on complex formation of mercury species with the emetine dithiocarbamate (emetine-CS 2) ligand, HPLC separation, and tris(2,2′-bipyridine)ruthenium(III) chemiluminescence detection. The complexation reactions of the mercury species and emetine-CS 2 ligand occurred instantaneously upon the addition of emetine-CS 2 solution to the solution containing the mercury species. The complete separation of these complexes was achieved using an ODS column with 20 mM NaH 2PO 4-acetonitrile (52:48, v/v) containing 30 mM NaClO 4 as an ion-pair reagent. The calibration graphs of these complexes were linear in the range from 1-100 μg/L. The detection limits were 0.27 μg/L, 0.33 μg/L, 0.39 μg/L, and 0.17 μg/L for methylmercury, ethylmercury, phenylmercury, and the mercury ion, respectively, at a signal-to-noise ratio of 3. The developed technique was validated by analyzing certified reference materials, CRM7402-a (cod fish, NMIJ) and CE464 (tuna fish, ERM), in combination with sonication-assisted acid leaching and liquid-liquid extraction. The emetine-CS 2 ligand has been used for extraction, separation, and detection of mercury species. The results determined using the proposed method were in good agreement with the values of the certified reference materials. The MeHg + and EtHg + recoveries for the spiked samples were found to be almost 100%. © 2011 Taylor and Francis Group, LLC.

DOI： 10.1080/00032719.2011.565442

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Ishiguro S.I., Umebayashi Y., Kanzaki R., Fujii K. . Structure, solvation, and acid-base property in ionic liquids . Pure and Applied Chemistry82 ( 10 ) 1927 - 1941 2010年10月査読

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Pure and Applied Chemistry

Ionic liquids (ILs) are expected to have specific properties as solvents for chemical reactions in view of solution chemistry. Among physicochemical properties, liquid structure, acid-base, and electron-pair donating and accepting abilities of solvent play a crucial role in ion-solvation and acid-base, metal-ion complexation, and electrochemical reactions. Various types of ILs have been developed, and among others, the bis(trifluoromethanesulfonyl) amide (TFSA-)-based ILs are extensively used. TFSA- is a flexible molecule to give two stable conformers, cis (C1) and trans (C2), which are present in equilibrium in the liquid state. The conformational equilibrium shifts upon solvation to the metal ion. This is quantitatively studied to obtain thermodynamic parameters of conformational change from C2 to C1 in the bulk and in the solvation sphere of the lithium ion. On the other hand, with ethylammonium nitrate (EAN), a typical protic IL, it is revealed that the ammonium group is hydrogen-bonded with three nitrate ions to form a heterogeneous liquid structure. The solvent acid-base property of EAN and acid dissociation reaction in EAN have been quantitatively revealed, and the results will be discussed in comparison with those in normal molecular solvents. Copyright © 2010 IUPAC, Publication date (Web): 19 June 2010.

DOI： 10.1351/PAC-CON-09-10-28

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神﨑亮 . イオン液体の酸塩基性とpH測定 . Electrochemistry78 ( 8 ) 687 - 692 2010年8月招待査読

Kanzaki R., Song X., Umebayashi Y., Ishiguro S.I. . Thermodynamic Study of the Solvation States of Acid and Base in a Protic Ionic Liquid, Ethylammonium Nitrate, and Its Aqueous Mixtures . Chemistry Letters39 ( 6 ) 578 - 579 2010年6月査読

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Chemistry Letters

Ethylammonium nitrate (EAN) is a typical protic ionic liquid (PIL) known for a long time. In order to investigate acidbase reaction mechanisms in PIL, thermodynamic quantities of a reaction, which corresponds to autoprotolysis in amphoteric solvents, has been determined in neat EAN. Unlike H3O + and OH- in water, proton donor and acceptor species in EAN are both neutral; this makes acid-base reaction mechanisms in EAN distinct from that in water. EAN-water mixtures have also been studied. © 2010 The Chemical Society of Japan.

DOI： 10.1246/cl.2010.578

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Toshiyuki Takamuku, Miho Tanaka, Takunosuke Sako, Takuya Shimomura, Kenta Fujii, Ryo Kanzaki, Munetaka Takeuchi . Solvation of the Amphiphilic Diol Molecule in Aliphatic Alcohol−Water and Fluorinated Alcohol−Water Solutions . The Journal of Physical Chemistry B114 ( 12 ) 4252 - 4260 2010年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：American Chemical Society (ACS)

We investigated the solvation properties of aqueous solutions of aliphatic alcohols and fluorinated alcohols. These included ethanol (EtOH), 2-propanol (2-PrOH), 2,2,2-trifluoroethanol (TFE), and 1,1,1,3,3,3-hexafluoro2-propanol (HFIP). The amphiphilic diol, 1,4-pentanediol (1,4-PD), was used as the solute to probe solvation properties at the molecular level. Small-angle neutron scattering (SANS) experiments revealed that the inherent microheterogeneity of HFIP-water binary solutions was significantly enhanced by addition of 1,4-PD. In contrast, the addition of 1,4-PD to EtOH-, 2-PrOH-, and TFE-water solutions hardly changed the mixing state. Molecular dynamics simulations were used to obtain the spatial distribution functions for the oxygen atom of water molecules and the carbon and fluorine atoms of alcohol molecules around 1,4-PD. Of the alcohols studied, these spatial distributions illustrated that HFIP molecules formed the strongest hydrophobic solvation shell around the hydrocarbons of 1,4-PD. This preferential solvation of 1,4-PD by HFIP leads to enhancement of HFIP clusters in the solutions. 13C NMR and infrared spectroscopic measurements on 1,4PD in the different alcohol-water solutions suggested that the number of water molecules around the hydrocarbons of 1,4-PD decreased in aliphatic alcohol-water solutions. Additionally, HFIP molecules are thought to strongly interact with the hydrocarbons of 1,4-PD in HFIP-water solutions. © 2010 American Chemical Society.

DOI： 10.1021/jp9097414

Ryo Kanzaki, Takushi Mitsugi, Shuhei Fukuda, Kenta Fujii, Munetaka Takeuchi, Yasufumi Soejima, Toshiyuki Takamuku, Toshio Yamaguchi, Yasuhiro Umebayashi, Shin-ichi Ishiguro . Ion-ion interaction in Room Temperature Ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate studied by large angle X-ray scattering experiment and molecular dynamics simulations . Journal of Molecular Liquids147 77 - 82 2009年査読

Yasuhiro Umebayashi, Takushi Mitsugi, Kenta Fujii, Shiro Seki, Kazumi Chiba, Hideo Yamamoto, Jpse N. Canongia Lopes, Agilio A. H. Padua, Munetaka Takeuchi, Ryo Kanzaki, Shin-ichi Ishiguro . Raman Spectroscopic Study, DFT Calculations and MD Simulations on the Conformational Isomerism of N-Alkyl-N-methylpyrrolidinium Bis-(trifluoromethanesulfonyl) Amide Ionic Liquids . The Journal of Physical Chemistry B113 4338 - 4346 2009年査読

Yasuhiro Umebayashi, Wan-Lin Chung, Takushi Mitsugi, Shuhei Fukuda, Munetaka Takeuchi, Kenta Fujii, Toshiyuki Takamuku, Ryo Kanzaki, Shin-ichi Ishiguro . Liquid Structure and the Ion-Ion Interactions of Ethylammonium Nitrate Ionic Liquid Studied by Large Angle X-Ray Scattering and Molecular Dynamics Simulations . Journal of Computer Chemistry, Japan7 125 - 134 2008年11月査読

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