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61.
62.
Katsuyuki Ogura Kunio Sanada Kazumasa Takahashi Hirotada Iida 《Tetrahedron letters》1982,23(39):4035-4038
Ethyl 2-acetylalkanoate gave ethyl 2-(methyl- or phenylthio)alkanoate in high yield on treatment wiht CH3SSO2CH3, PhSSO2Ph, or PhSSPh in the presence of small excess of EtONa in EtOH. Application of the present method to synthesis of pellitorine and the queen substance is also described. 相似文献
63.
127I M?ssbauer spectra of good quality were obtained at 20 K using a Zn127mTe source produced by high flux neutron irradiation of 66Zn-126Te at reactor core. The M?ssbauer spectra for KI and some iodine(III) compounds with absorption intensity of about 5% suggest that the 127I M?ssbauer spectroscopy is useful in elucidating the bonding nature of the iodine compounds. Preparative method of the M?ssbauer source and experimental technique are reported in detail. 相似文献
64.
Raman spectra of stilbene mono- and di-negative ions in tetrahydrofuran solution were obtained by Ar+ laser exciting lines. A considerable frequency shift was observed for several vibrations in the successive steps: stilbene → (stilbene)? → (stilbene)2?. The observed shift is discussed in a simple VB scheme, particularly in comparison with the results on anthracene negative ions. The resonance Raman effect was striking for both ions with intensity maxima at the exciting wavelengths close to the absorption maxima. 相似文献
65.
Fujitani T Nakamura I Kobayashi Y Takahashi A Haneda M Hamada H 《The journal of physical chemistry. B》2005,109(37):17603-17607
Adsorption and reactions of NO on clean and CO-precovered Ir(111) were investigated by means of X-ray photoelectron spectroscopy (XPS), high-resolution electron energy loss spectroscopy (HR-EELS), infrared reflection absorption spectroscopy (IRAS), and temperature-programmed desorption (TPD). Two NO adsorption states, indicative of fcc-hollow sites and atop sites, were present on the Ir(111) surface at saturation coverage. NO adsorbed on hollow sites dissociated to Na and Oa at temperatures above 283 K. The dissociated Na desorbed to form N2 by recombination of Na at 574 K and by a disproportionation reaction between atop-NO and Na at 471 K. Preadsorbed CO inhibited the adsorption of NO on atop sites, whereas adsorption on hollow sites was not affected by the coexistence of CO. The adsorbed CO reacted with dissociated Oa and desorbed as CO2 at 574 K. 相似文献
66.
Hong-Ling Li Koichi Takahashi Yusuke Ujihira Mariko Ishiwatari Kurima Kobayashi Takahiko Iriyama Tokuzo Konishi 《Journal of Thermal Analysis and Calorimetry》1995,45(6):1359-1371
The Mössbauer spectra of Sm2Fe17Nx, prepared by the nitrogenation of Sm2Fe17 powders in an ammonia and hydrogen atmosphere, were observed at elevated temperatures to shed light on the thermal behavior of nitrogen in the compounds Sm2Fe17Nx. It was found that there were large differences in thermal behavior between the starting Sm2Fe17, crystalline Sm2Fe17Nx (x≈1.7) and amorphous Sm2Fe17Nx(x~7). The thermal decomposition behavior of Sm2Fe17N3.2, developed as one of the most promising hard magnetic materials, was found to be different under different atmospheres. 相似文献
67.
Saito TK Takahashi M Muguruma H Niki E Mabuchi K 《Journal of photochemistry and photobiology. B, Biology》2001,61(3):114-121
We report a new aspect of rapid (<30 s) light-induced cell membrane damage photosensitized by 5,5"-bis(aminomethyl)-2,2':5',2"-terthiophene dihydrochloride (BAT), which is a water-soluble alpha-terthienyl analogue, using a high-power laser (light intensity 1.6 W cm(-2)). In this paper, we will discuss the relationship between the exposure time of the cells to the photosensitizer and the phototoxic process. Three toxic processes can be identified: first, a non-light-mediated toxicity dependent on BAT-cell incubation; second, a phototoxicity independent of BAT exposure time when the BAT concentration is in the 2-10-microM range; third, a phototoxicity dependent on BAT exposure time when BAT concentration becomes 20 microM. The cytotoxicity decreases when alpha-tocopherol, an antioxidant, is added to a cell membrane. This pattern of phototoxicity is the typical of a phospholipid peroxidation chain reaction and oxidative damage of membrane proteins triggered by a reactive oxygen species generated by a triplet state of BAT. The BAT exposure time is clearly correlated with the partition of the photosensitizer in the cell membrane and inside the cell. 相似文献
68.
Summary The retention, enantionselectivity and enantiomeric elution order of racemic propranolol (PP) and its ester derivatives (O-acetyl,-propionyl,-butyrul and-valeryl PP) on an 1-acid glycoprotein (AGP)-bonded column have been investigated by changing eluent composition (eluent pH, buffer concentration, type and content of organic modifier). The retention of these cationic solutes, PP and its ester derivatives, was influenced by eluent pH, ionic strength and organic modifier content. The enantioselectivity was dependent on eluent pH and type of organic modifier. Reversal of the enantiomeric elution order of ester derivatives of PP (O-propionyl-butyryl) and-valeryl PP) occurred around eluent pH 6–7. These results suggst that chiral recognition or binding properties may be altered by the change in eluent composition, espeically eluent pH and type of organic modifier. 相似文献
69.
Toshio Yamanaka Mitsuru Ohkubo Fumie Takahashi Masayuki Kato 《Tetrahedron letters》2004,45(13):2843-2845
An efficient synthesis of the orally-active GpIIb/IIIa antagonist FR184764 was achieved. The key intermediate, an optically active ethynyl β-amino ester, was synthesized efficiently by utilizing a lipase catalyzed kinetic resolution step. 相似文献
70.
Fukuji Higashi Yuko Mihara Ikuo Takahashi Wen-Hsin Chen Tech-Chou Chang 《Journal of polymer science. Part A, Polymer chemistry》1985,23(11):2851-2856
The reaction promoted by Vilsmeier adduct derived from tosyl chloride (TsCl) with N,N-dimethylformamide (DMF) was successfully applied to the preparation of copolyesteramides of high molecular weights directly from aromatic dicarboxylic acids, diamines, and bisphenols. The polycondensation was significantly affected by the reaction of activated dicarboxylic acids with bisphenols and diamines. Addition of a mixture of bisphenols and diamines likely caused gelation of the reaction mixtures, resulting in insoluble polymers, especially with high mol % diamines. Stepweise addition of them, however, gave the homogeneous reaction mixtures and copolymers of better solubility. These phenomena were studied in terms of sequence length distribution of polyester units, which was estimated by thermal analyses of the random copolymers prepared under various conditions for the initial reaction with bisphenols. 相似文献