Solvent effect of ionic liquids on the distribution constant of 2–thenoyltrifluoroacetone

金沢大学理工研究域物質化学系Distribution constants of 2-thenoyltrifluoroacetone (Htta) and its Ni(II)and Cu(II) chelates between 1-alkyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (Cn mimTf2N; n = 4, 6, and 8) as ionic liquid (IL) and an aqueous phase were determined. The enol fraction of Htta in ILs was spectrophotometrically measured to calculate the distribution constant of the enol form (KD,HE) of Htta. The KD,HE values in ILs were evaluated by comparing those in various molecular solvents such as alkanes, aromatic hydrocarbons, chlorohydrocarbons, ethers, ketones, and esters previously reported on the basis of the regular solution theory (RST). It was elucidated that the IL solutions of Htta (enol) can be taken as apparently regular solutions as expected in the organic solvents. On the other hand, the effect of ILs on the distribution constant of metal(II) chelates (KD,M) was fairly complicated. The Cu(tta)2-IL solutions behaved like the alkane and aromatic hydrocarbon solutions but the Ni(tta)2-IL (C4mimTf2N) like ether and ketone solutions. In the Ni(II) case, some specific interactions between the Ni(II) chelate and IL was suggested. Finally, the solubility parameters of ILs were calculated using KD,HE by RST and were in good agreement with the literature values obtained by the enthalpy of vaporization. © 2010 Elsevier B.V. All rights reserved

NMRを用いる新規な不足当量同位体希釈分析法による環境有機物質の絶対定量

地球規模での環境保全,国際貿易,健康と安全に関わる分析値の質の保証が国際的に重要な課題となっており,様々な無機・有機物質に対してSIトレーサビリティが証明された信頼性の高い分析法が必要である。本研究では,定量目的成分として生体・環境関連物質の含酸素有機化合物を取り上げ,従来の基準分析法である同位体希釈質量分析に代わる新規な絶対定量法として,不足当量NMR分析法を開発する。信頼性評価のために分析法バリデーションを行い,有用性を明らかにする。1)フタル酸ジ-2-エチルヘキシル(DEHP),ジメチルスルホキシド(DMSO),ポリエチレングリコール400ジメチルエーテル(PEG),ポリオキシエチレン(10)オクチルフェニルエーテル(TX100)を取り上げ,Eu(III)とPr(III)のヘキサフルオロアセチルアセトン(Hhfa)錯体との付加錯体生成を溶媒抽出法を用いて研究した。DEHP,DMSO,TX100は,いずれも1:1と1:2付加錯体を生成し,PEG400は1:1錯体のみを形成することが分かり,それぞれの生成定数を決定した。これらの有機化合物とランタニド錯体を共存させ1H-NMRスペクトルを測定し,溶媒抽出の結果を考慮して解析し,付加錯体生成定数を求めた。2)ランタニド錯体による有機化合物の1H NMRの化学シフト変化を利用した新規な絶対定量法を提案した。DMSOをモデル試料としEu(hfa)_3による不足当量錯形成の最適条件を検討し,定量法の精度・正確さについて評価した。試料溶液に不足一定量のEu(hfa)_3を加え,既知量のDMSOあるいはDMSO-d_6をスパイクすることにより,未知量のDMSO濃度を提案した定量式に基づき決定した。定量値は相対標準偏差が0.8-2.1%、相対誤差が0.2-1.5%であり,検量線なしで精度良く正確に定量できることを示した。A novel analytical method of substoichiometric nuclear magnetic resonance analysis (SNMR) for oxygen-containing organic compounds (000 has been proposed The present method is based on the adduct formation of a paramagnetic lanthanide (III) (Ln) chelate as a shift reagent with OOC. The stoichiometry and the equilibrium of the adduct formation of tris(hexafluoroacetylacetonato)-europium(III)(Eu(hfa)_3) or -praseodymium(III) (Pr(hfa)_3) with OOC such as di(2-ethylhexyl) phthalate (DEHP), dimethyl sufoxide (DMSO), poly(ethylene glycol 400) dimethyl ether (PEG), and polyoxyethylene(10) octylphenyl ether (TX100) were studied by the solvent extraction method. The composition of the adducts of Ln(hfa)_3 was found to be only 1:1 for PEG and 1:1 and 1:2 for DEHP, DMSO, and TX100, and the respective adduct formation constants were determined. From the equilibrium analysis by \u27H NMR, the adduct formation constant and the chemical shift of OOC protons in the adduct were obtained. This knowledge led to develop SNMR for OOC. The validity of SNMR was demonstrated by the determination of DMSO in a synthetic solution. A substoichiometric amount of Eu(hfa)_3 was added to the sample solution of DMSO and the chemical shift of the methyl-protons was measured by NMR. After a known amount of DMSO was spiked to the sample solution, the chemical shift was measured, and then the amount of DMSO in the sample was calculated. The mM level of DMSO could be determined by only measuring the chemical shift for the analyte without any calibration curves. The repeatability of the chemical shift measurement was as good as 0.01% as relative standard deviation, and the precision and accuracy for the determined values were very high.研究課題/領域番号:18550066, 研究期間(年度):2006-2007出典：「NMRを用いる新規な不足当量同位体希釈分析法による環境有機物質の絶対定量」研究成果報告書　課題番号18550066 (KAKEN：科学研究費助成事業データベース（国立情報学研究所）)　　　本文データは著者版報告書より作

Ion transfer and adsorption behavior of ionizable drugs affected by PAMAM dendrimers at the water|1,2- dichloroethane interface

The transfer and adsorption reactions of ionizable drug molecules, i.e. dipyridamole (DIP), propranolol (PRO) and warfarin (WAR), at the water|1,2-dichloroehtane (DCE) interface were studied in the presence of the carboxylate- terminated generation 3.5 (G3.5) or amino-terminated generation 4 (G4) polyamidoamine (PAMAM) dendrimers. The ionic partition diagram of the ionizable drugs was determined through the voltammetric analysis of ion transfer responses. In the DIP system, the additional voltammetric responses associated with the interfacial adsorption were observed in the positive potential region. Although the spectroscopic features of the drug species in the aqueous solution were hardly affected by the addition of the dendrimers, the ion transfer currents in the DIP and PRO systems were decreased in the presence of the G3.5 PAMAM dendrimer indicating the intermolecular association between the cationic drugs and negatively charged dendrimers in the interfacial region. The interfacial mechanism of the fluorescent DIP species was investigated in detail by potential-modulated fluorescence (PMF) spectroscopy. The PMF results demonstrated that the monoprotonated form, HDIP+, was transferred across the water|DCE interface accompanied by the adsorption process. The interfacial mechanism of the DIP species was significantly modified by the dendrimer, depending on the pH condition. Under acidic conditions, the positively charged G3.5 PAMAM dendrimer adsorbed at the interface effectively prevented the coadsorption of HDIP+. At higher pHs, DIP (or HDIP+) interacted with the hydrophobic interior moiety (or negatively charged periphery) of the dendrimers. © 2016 Elsevier Ltd. All rights reserved.Embargo Period 24 months / This article has Supplementary data

Enhancement of the extraction of lanthanide(III) with 2- thenoyltrifluoroacetone in the presence of foreign metal(III) ions: Coextraction of light lanthanide(III) with Al3+, Sc3+ and Fe 3+

金沢大学大学院自然科学研究科物質情報解析Enhancement of the extraction, or coextraction of lanthanide(III) (Ln) with metal(III) ions (M3+) such as Al3+, Sc3+, and Fe3+ was found in a typical chelate extraction system of 2-thenoyltrifluoroacetone (Htta)-benzene. The distribution ratio of La 3+ was enhanced by a factor of 6 with 3.0 x 10-2 M Al 3+, while that of Lu3+ was not affected at all. The magnitude of the coextraction decreased with the atomic number of Ln. Equilibrium analysis and spectroscopic studies indicated that the coextraction was ascribed to the formation of the 1:1 adduct between Ln(tta)3 and M(tta)3 extracted into the organic phase. The overall equilibrium of the coextraction was expressed as Ln3+ + M3+ + 6 Htta org ⇌ Ln(tta)3(M(tta)3)org + 6 H+

Molecular association between flavin derivatives and dendritic polymers at the water|1,2-dichloroethane interface

The ion transfer and adsorption mechanism of flavin derivatives, riboflavin (RF) and flavin mononucleotide (FMN), at the polarized water|1,2-dichloroethane (DCE) interface were studied in the presence of the fourth generation (G4) amino-terminated polyamidoamine (PAMAM) dendrimer or hyperbranched bis-MPA polyester-64-hydroxyl (HBP). The flavin derivatives associated with the positively charged G4 PAMAM dendrimer both in the aqueous solution and at the water|DCE interface. Spectroelectrochemical analysis through potential-modulated fluorescence spectroscopy demonstrated that the dendrimer-bound flavin derivatives were transferred across the water|DCE interface in the positive potential region, while the interfacial adsorption of flavin derivatives in the negative potential region was effectively inhibited by the competitive adsorption of the neutral G4 HBP molecules. © 2016 Elsevier B.V.Embargo Period 12 months / This article has Supplementary material of the different file

An 8-sulfonamidoquinoline derivative with imidazolium unit as an extraction reagent for use in ionic liquid chelate extraction systems

金沢大学理工研究域物質化学系To evaluate the superiority of using a task-specific onium salt (TSOS), a novel TSOS reagent 1-methyl-3-[2-(8-quinolinylaminosulfonyl)ethyl]imidazolium chloride (HmimesqCl) was synthesized, and its performance in extraction of different divalent metal cations was investigated. This TSOS reagent has both a cationic imidazolium unit and an anionic (proton-dissociable) complexation unit for the extraction of metal cations into an ionic liquid. In the use of HmimesqCl, relatively high extraction of metals resulted in comparison with the use of its non-imidazolium analogs, without changing the extraction selectivity. © 2010 Elsevier B.V

Spectroelectrochemical characterization of dendrimer-porphyrin associates at polarized liquid|liquid interfaces

Molecular encapsulation of anionic porphyrins in NH2-terminated polyamidoamine (PAMAM) dendrimers and the interfacial behavior of the dendrimer-porphyrin associates were studied at the polarized water|1,2-dichloroethane (DCE) interface. Formation of the ion associates was significantly dependent on the pH condition and on generation of dendrimers. 5,10,15,20-Tetrakis(4-sulfonatophenyl)porphyrin (ZnTPPS4-) associated with the positively charged fourth-generation (G4) PAMAM dendrimer was highly stabilized in acidic aqueous solution without protolytic demetalation in a wide range of pH values (pH > 2). In contrast to the zinc(II) complex, the free base porphyrin (H2TPPS4-) was readily protonated under acidic conditions even in the presence of the dendrimers. In addition, the J-aggregates of diprotonated species, (H4TPPS2-) n, were preferably formed on the dendrimer. The interfacial mechanism of the dendrimer-porphyrin associates was analyzed in detail by potential-modulated fluorescence (PMF) spectroscopy. PMF results indicated that the dendrimers incorporating porphyrin molecules were transferred across the positively polarized water|DCE interface via adsorption step, whereas the transfer responses of the porphyrin ions released from the dendrimers were observed at negatively polarized conditions. A negative shift of the transfer potential of porphyrin ions compared to the intrinsic transfer potential was apparently observed for each ion association system. The ion association stability between the dendrimer and the porphyrin molecules could be estimated from a negative shift of the transfer potential. ZnTPPS4- exhibited relatively strong interaction with the higher generation dendrimer, whereas H2TPPS4- was less effectively associated with the dendrimers. © 2014 American Chemical Society

Extraction of Cu(II) with dioctyldithiocarbamate and a kinetic study of the extraction using a two-phase microflow system

金沢大学理工研究域物質化学系Extraction of Cu(II) with dialkyldithiocarbamates and the extraction kinetics have been studied using a two-phase microflow system. The extraction behavior of Cu(II) with potassium dioctyldithiocarbamate (Kdodtc) was investigated using a batch method to determine the propertes of the synthesized Kdodtc. The extraction ability of dodtc was much greater than that of diethyldithiocarbamate (dedtc) under acid conditions. On the other hand, at higher pH values in the range of 8 - 13, the extraction of Cu(II) with dodtc decreased with increasing pH. This phenomenon was ascribed to the formation of micelles and/or an emulsion, which was caused by the amphiphilic properties of dodtc. The extraction kinetics of Cu(II) was investigated using a glass microchip which was connected to microsyringe pumps and a UV/Vis capillary LC detector. The initial rate constant (kapp) determined for dodtc was greater than that with dedtc. From the relationship between the dodtc concentration and kapp, it was suggested that the extraction rate was governed by the formation of the dodtc complex at the liquid-liquid interface

Potential-Dependent Adsorption and Orientation of meso-Substituted Porphyrins at Liquid|Liquid Interfaces Studied by Polarization-Modulation Total Internal Reflection Fluorescence Spectroscopy

Potential-dependent adsorption behavior of meso-substituted water-soluble porphyrins at the polarized water|1,2-dichloroethane (DCE) interface was studied by polarization-modulation total internal reflection fluorescence (PM-TIRF) spectroscopy. In the PM-TIRF experiments, the fluorescence signal from the interfacial region was analyzed as a function of the periodic modulation of linear-polarizations (p and s) of the incident excitation beam. The potential-dependence of PM-TIRF responses for meso-substituted porphyrins, 5,10,15,20-tetrakis(N-methylpyridyl)porphyrin (H2TMPyP4+) and 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin (H2TPPS4-), indicated that both free base porphyrins were adsorbed with relatively lying orientations at the polarized water|DCE interface. The average orientation angles (θ) were estimated as θ = 61 ± 1°for H2TMPyP4+ and θ = 65 ± 1°for H2TPPS4- with respect to the interface normal. The wavelength-dependence of polarization-modulated fluorescence signals (PM-TIRF spectrum), which corresponds to "pure" emission spectrum of interfacial species, clearly indicated that H2TMPyP4+ and H2TPPS4- are adsorbed with a modification of the solvation at the interface. These results demonstrated a high ability of the PM-TIRF spectroscopy for the direct characterization of fluorescent species adsorbed at polarized liquid|liquid interfaces. © 2016 American Chemical Society.Embargo Period 12 months / This article has Supplementary dat

Correlation of vascular endothelial cell proliferation with microvessel density and expression of vascular endothelial growth factor and basic fibroblast growth factor in hepatocellular carcinoma

Tumor-associated angiogenesis is essential for tumor growth or metastasis, and consists of multiple and sequential steps regulated by proangiogenic and antiangiogenic factors. Vascular endothelial cell proliferation is involved in this process. We investigated the correlation of vascular endothelial cell proliferation with microvessel density (MVD) and expression of major proangiogenic molecules, vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in hepatocellular carcinoma (HCC). Formalin-fixed paraffin-embedded specimens of surgically resectedHCCfrom67 patients were used. Proliferating endothelial cells were detected by immunofluorescence double staining for CD34 and proliferating cell nuclear antigen (PCNA). The proliferation activity of endothelial cells was determined by the rate of PCNA-positive endothelial cells, and evaluated at the periphery and center of the tumors and adjacent non-neoplastic livers. MVD and the expression of VEGF and bFGF in the tumors were also examined immunohistochemically. The proliferation activity of endothelial cells at the periphery of the tumors was significantly higher than that at the center of the tumors (35.8% vs.12.7%, P<0.0001). The rate of PCNA positive endothelial cells in the tumors with higher bFGF expression was significantly higher than that in the tumors with lower bFGF expression (44.8% vs. 32.5%,P<0.005) at the periphery of the tumors. There was no significant correlation between the rate of PCNA-positive endothelial cells and clinicopathological findings or MVD. InHCC, the proliferation activity of vascular endothelial cells is suggested to be heterogeneous in the tumor and higher at the periphery of the tumor, and bFGF may play an important role in the positive regulation of tumor-associated vascular endothelial cell proliferation