78 research outputs found

    Oxidation of pyrrole-2-carboxylates with o-chloranil and its synthetic application

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    金沢大学理工研究域物質化学系t-Butyl 3,4-dialkyl-1H-pyrrole-2-carboxylates were oxidized with ochloranil in the presence of MeOH to afford the corresponding 5-methoxypyrrolin-2-one derivatives. The resulting 5-methoxypyrrolin-2-one was reacted with various nucleophiles under acidic conditions to afford the functionalized pyrrolinone derivatives in good yields. © The Japan Institute of Heterocyclic Chemistry

    Effect of Film-Forming Additive in Ionic Liquid Electrolyte on Electrochemical Performance of Si Negative-Electrode for LIBs

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    1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide (EMI-TFSA) is one of the promising ionic liquids as electrolyte solvent to enhance the electrochemical performance of Si electrode for Li-ion batteries (LIBs) because of its low viscosity and high conductivity. However, it has low stability against reduction and its reductive decomposition product inhibits Li+ insertion to electrodes, leading to poor cycling stability. To exert a potential of EMI-TFSA, we employed vinylene carbonate (VC) as film-forming additive. Si electrode exhibited very high cycling stability and rate capability in 20 vol.% VC-added EMI-TFSA-based electrolyte. In addition, by replacing TFSA anion with bis(fluorosulfonyl)amide (FSA) for Li salt and ionic liquid solvent, an excellent cycling performance and outstanding rate capability was achieved. VC cannot only fabricate a good surface film but also lower the interaction between Li+ and FSA-, providing smooth desolvation of FSA- to obtain better high-rate performance. Non-flammability of the VC-added electrolytes was confirmed by fire resistance test in closed-system: no ignition was observed even at 300°C. Consequently, we found that mixture electrolyte consisted of EMI-based ionic liquid and VC, especially 1 M LiFSA/EMI-FSA with 20 vol.% VC, is a prospective candidate for simultaneously enhancing the electrochemical performance of Si electrode as well as safety of LIBs

    ウラン-トリウム-鉛壊変系列における初生放射非平衡の補正及びレーザーアブレーション誘導結合プラズマ質量分析法を用いた第四紀ジルコン年代測定法の開発

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    京都大学0048新制・課程博士博士(理学)甲第18803号理博第4061号新制||理||1584(附属図書館)31754京都大学大学院理学研究科地球惑星科学専攻(主査)教授 平田 岳史, 教授 田上 高広, 教授 土`山 明学位規則第4条第1項該当Doctor of ScienceKyoto UniversityDGA

    Possible polymetamorphism and brine infiltration recorded in the garnet–sillimanite gneiss, Skallevikshalsen, Lützow–Holm Complex, East Antarctica

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    Chlorine–rich (>0.3 wt%Cl) biotite inclusions in the core of garnet porphyroblasts in the garnet–sillimanite (Grt–Sil) gneiss from Skallevikshalsen, Lützow–Holm Complex (LHC), East Antarctica is estimated to be stable under >1.2 GPa, 820–850 °C, coexisted with granitic melt as suggested by the nanogranite/felsite inclusions. Rare occurrence of matrix biotite, in spite of the common occurrence of biotite as inclusions in garnet, suggests almost complete consumption of pre–existed matrix biotite during the prograde to peak metamorphism. Brine infiltration during prograde to peak metamorphism in Skallevikshalsen is supported by Cl–rich scapolite described in previous studies. Brine infiltration and progress of continuous biotite–consuming melting reactions were probably responsible for elevating the Cl content of biotite in the studied sample. In situ electron microprobe U–Th–Pb dating of monazite and the in situ laser ablation inductively coupled plasma mass spectrometry (LA–ICPMS) U–Pb dating of zircon in the Grt–Sil gneiss revealed that both monazite and zircon has the 'older age population' with ~ 650–580 Ma and the 'younger age population' with ~ 560–500 Ma. The REE and trace element pattern of one of the P–rich patches in the garnet core is different from the P–rich garnet rim. The isotope mapping of the same patch by LA–ICPMS revealed that the patch is also observed as a domain depleted in ⁵¹V, ⁸⁹Y, ¹⁶⁵Ho, ¹⁶⁶Er, ¹⁶⁹Tm, ¹⁷²Yb, and ¹⁷⁵Lu. Clear difference in ⁵¹V concentration between the patch and the garnet rim suggests that this patch is not a continuous part from the garnet rim, but is likely a relic of preexisted garnet. Kyanite included in the patch suggests that the precursor rock was presumably a medium– to high–pressure type metamorphic rock. Presence of the older age population (~ 650–580 Ma) monazites in Skallevikshalsen and Skallen also suggest that rocks in these areas experienced polymetamorphism, and resetting by the ~ 560–500 Ma metamorphic event was incomplete in these areas. Taking into account the presence of Cl–rich biotite inclusions in garnet, infiltration of brine accompanied by partial melting is one probable event that took place at ~ 560–500 Ma in the Skallevikshalsen area, and part of the monazite possibly recrystallized by this brine infiltration. Detailed microstructural observation using trace element mapping combined with detailed petrography especially focusing on the Cl–bearing minerals as a tracer of brines would become a powerful tool for better interpreting the results of monazite and zircon dating and for investigating the fluid–related crustal processes
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