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31.
Yu. N. Ogibin A. I. Ilovaisky V. M. Merkulova G. I. Nikishin 《Russian Chemical Bulletin》1995,44(3):507-510
The effect of anions of the supporting electrolyte (F–, dialkylphosphate, TsO–, and BF
4
–
and other electrolysis conditions (anode material, temperature, substrate concentration) on the selectivity of the direct anodic oxidation ofp-methoxytoluene in methanol into 4-methoxybenzaldehyde dimethylacetal was studied. The highest selectivity was obtained in the presence of fluoride anion.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 524–527, March, 1995.This work was financially supported by the Ministry of Science, High School and Technical Policy of the Russian Federation within the scope of the State scientific-technical program Ecologically harmless processes of chemistry and chemical technology (project No. 1.140 Low-tonnage chemical products) and by the International Science Foundation (Grant Ch-2-1246-0923). 相似文献
32.
IntroductionInthcsclcctivcoxidationofalkanes.suchas'theoxidativccouplingofmcthanc(0CM)andthcoxidativcdch}'drogenationofcthanc(0DE)t0prcparccth}'lene.bothoxidcionsofthelatticeandtheox}'genspeciesovercataIystsuffocepla}'animportantrole.Althoughcxtcnsivcinvcstigationshavcbeengivcntothecharactcrizationofox}'gcnspccicsandthcreactionofox}'gcnspecicsx`ithalkanes,itisstilldifficulttosayt`hichoncsofox}'gcnspcciesarcthcactivcspecicsinthcactivation0falkancs.bccauscthenaturcofcatal}'stsandthecxperimcntc… 相似文献
33.
Susumu Yonezawa Shiori Nishibu Masayuki Takashima 《Journal of fluorine chemistry》2007,128(4):438-447
The preparation of the rare earth containing oxide fluoride glasses LnF3 (Ln; Y through Lu)-BaF2-AlF3-GeO2 in which the nominal content of LnF3 reached 60 mol% in maximum and their basic properties such as density, refractive index and glass transition temperature were investigated and summarized in detail. Especially, in order to discuss the local structure around the rare earth ion in the glass, the Judd-Ofelt analysis (discussion with Ω parameters) of the HoF3-BaF2-AlF3-GeO2 glasses was carried out. The unique fluorescent behavior and the magnetic properties of LnF3-BaF2-AlF3-GeO2 glasses (Ln = Tb and/or Sm) were also studied. 相似文献
34.
Masafumi Kobayashi Tetsuya Inoguchi Takashi Iida Takashi Tanioka Hiroshi Kumase Yasushi Fukai 《Journal of fluorine chemistry》2003,120(2):2838-110
Direct fluorination of 1,3-dioxolan-2-one with elemental fluorine was successfully carried out to provide 4-fluoro-1,3-dioxolan-2-one, which was expected as an additive for lithium ion secondary battery. 4-Fluoro-1,3-dioxolan-2-one was also further fluorinated with elemental fluorine to give three isomers of difluoro derivatives by the same methodology. Another topic is the preparation of trifluoromethanesulfonyl fluoride, an intermediate of lithium battery electrolyte, by the reaction of methanesulfonyl fluoride with elemental fluorine. The use of perfluoro-2-methylpentane as a solvent gave satisfactory selectivity of trifluoromethanesulfonyl fluoride. 相似文献
35.
A new chemical method is reported for the determination of total fluoride in complex liquids and suspensions, such as fruit juices, urine, serum and blood. It is based on the formation of the A1F radical in a graphite furnace afterin situ oxygen-assisted ashing of the untreated sample. The absorbance of this radical is measured at 227.45 nm. The method is relatively easy to use and provides a low detection limit (14 ng/ml) and reasonable reproducibility (5–10%). 相似文献
36.
Cyclical bifurcated hydrogen bonded structures are proposed for aqueous solutions of hydrofluoric acid and for the bifluoride ion which are consistent with the spectral data. The structure proposed for HF is also applicable to solutions in organic solvents. Raman spectra of tetramethylguanidinium perchlorate suggest that the corresponding Raman spectra of perchloric acid solutions may not be interpreted in terms of a completely dissociated acid. Other evidence including activity coefficient, heat capacity and partial molal volume data suggest that there is some association in relatively dilute perchloric acid solutions between the perchlorate ion and the hydrated proton. This association decreases in concentrated aqueous solutions. 相似文献
37.
先在0.5 mol·L-1硝酸介质中活化氟离子选择性电极,再在含硝酸的总离子强度调节混合液(TISAM)中测定氟,线性范围为1×10-7~1×10-2mol·L-1,检出限为1.9μg·L-1。该方法应用于绿茶饮料、水、牛奶中痕量氟的测定,结果的RSD小于4.8%,回收率在96.1%至100.2%之间,对氟离子选择性电极在硝酸介质中的活化机理作了阐述。 相似文献
38.
I. V. Dlinnykh G. A. Golubeva I. F. Leshcheva V. V. Nesterov M. Yu. Antipin L. A. Sviridova 《Chemistry of Heterocyclic Compounds》2004,40(9):1142-1149
The reaction of oxindoles with 5-hydroxypyrazolidines on the surface of potassium fluoride-modified alumina leads to 3-(5-pyrazolidinyl)oxindoles. The structure of these products was studied. 相似文献
39.
研究了聚偏氟乙烯 (PVDF)自由基引发的氯化反应。考察了各种因素 ,如氯化剂、引发剂的种类及浓度 ,反应介质、反应温度和反应时间的影响 ,确定了合成氯化PVDF的最佳反应条件。采用碱熔法测定氯含量 ,用HNMR进行了结构表征 ,并用溶度参数法、接触角法、DTA TG等方法对PVDF氯化前后的溶解性、附着力、熔点等性能进行了测试。结果表明 ,氯原子成功地引入到了PVDF上 ,当氯含量增加到 8 3 %时 ,氯化PVDF的熔点由 1 63℃降至 1 3 0℃左右 ,附着力也有了明显的改善 ,与水的接触角由 90°降至 5 4°,由不溶于丙酮变为溶于丙酮 ,对甲醇和四氯化碳的溶度参数的变化也说明了氯化PVDF的溶解性能变好 ,由TG曲线可知 ,氯化PVDF的热稳定性比改性前虽有一定的降低 ,但其分解温度仍在 3 0 0℃以上 相似文献
40.
The system BaF2/AlF3 is investigated by X-ray and D.T.A., and the liquid-solid phase diagram is established. Five ternary fluorides are disclosed: trimorphic BaAlF5, Ba3Al2F12, Ba5AlF19, polymorphic Ba3AlF9 and Ba5AlF13. Neutron thermodiffractometry experiments are performed to specify some parts of the diagram. The cell parameters of the fluorides are given and the results are discussed and compared with those of the previous works. 相似文献