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991.
Sugiyama Y Sasamori T Hosoi Y Furukawa Y Takagi N Nagase S Tokitoh N 《Journal of the American Chemical Society》2006,128(3):1023-1031
The reduction of an overcrowded (E)-1,2-dibromodigermene, Bbt(Br)Ge=Ge(Br)Bbt (2) [Bbt = 2,6-bis[bis(trimethylsilyl)methyl]-4-[tris(trimethylsilyl)methyl]phenyl], with KC8 afforded a stable digermyne, BbtGe[triple bond]GeBbt (1). The Ge[triple bond]Ge triple-bond characters of 1 were revealed by the X-ray crystallographic analysis and spectroscopic studies (UV/vis and Raman spectra) together with theoretical calculations. The Ge[triple bond]Ge bond lengths of the two nonidentical molecules of 1 observed in the unit cell were shorter than that of the previously reported digermyne, Ar'Ge[triple bond]GeAr' (Ar' = 2,6-Dip2C6H3, Dip = 2,6-diisopropylphenyl). 相似文献
992.
Maeda Y Kanda M Hashimoto M Hasegawa T Kimura S Lian Y Wakahara T Akasaka T Kazaoui S Minami N Okazaki T Hayamizu Y Hata K Lu J Nagase S 《Journal of the American Chemical Society》2006,128(37):12239-12242
The dispersion of small-diameter single-walled carbon nanotubes (SWNTs) produced by the CoMoCAT method in tetrahydrofuran (THF) with the use of amine was studied. The absorption, photoluminescence, and Raman spectroscopies showed that the dispersion and centrifugation process leads to an effective separation of metallic SWNTs from semiconducting SWNTs. Since this method is simple and convenient, it is highly applicable to an industrial utilization for widespread applications of SWNTs. 相似文献
993.
Shindo M Kita T Kumagai T Matsumoto K Shishido K 《Journal of the American Chemical Society》2006,128(4):1062-1063
We have developed the E-selective olefination of ester carbonyls to afford tetrasubstituted, functionalized olefins and the C-S insertion of thiol esters to give beta-keto thiol esters via ynolates. 相似文献
994.
Hamura T Ibusuki Y Uekusa H Matsumoto T Siegel JS Baldridge KK Suzuki K 《Journal of the American Chemical Society》2006,128(31):10032-10033
We report herein the syntheses of dodecamethoxytricyclobutabenzene (TCBB) 1 and hexaoxo-TCBB 2, a class of molecules with structural and theoretical interest. The preparation is based on the 3-fold [2 + 2] cycloadditions of benzyne and ketene silyl acetals (KSAs), where the selectively protected 2-iodophloroglucinol derivative served as a synthetic equivalent of benztriyne I, allowing rapid and regioselective annulation of fully functionalized four-membered rings. Structural study on the former compound showed that the C-C bond lengths in the central benzene ring were essentially the same. 相似文献
995.
The dynamics of the reaction, V(a 4FJ)+NO-->VO(X 4Sigma-)+N was studied by using a crossed-beam technique at 16.4 kJ/mol of collision energy. The V atomic beam was generated by laser vaporization and crossed with the O2 beam at a right angle. The laser-induced fluorescence (LIF) for the transition of VO(B 4Pi-X 4Sigma) was used to determine the rotational state distribution of the reaction product in the vibrational ground state. Almost pure V(a 4FJ) beam was obtained by using the mixture of NH3 with N2 as a carrier gas. Comparing the LIF spectra of VO measured for two carrier gases, i.e., NH3N2 and pure N2, it was concluded that the vibrational ground state of VO(X 4Sigma-) is formed almost entirely from the reaction of V(a 4FJ) and the contribution of the metastable V(a 6DJ) is negligible. The observed rotational distribution was similar to a statistical prior prediction, and suggested that the title reaction proceeds via a long-lived intermediate, which is consistent with an electron transfer mechanism. 相似文献
996.
[reaction: see text] A new type of furan-iminium cation cyclization was developed and used to construct the ABC ring of manzamine A. The cyclization proceeded at the 2-position with complete regio- and stereoselectivity to give a spiro-center. The product was efficiently converted to the highly substituted core structure of manzamine A. 相似文献
997.
[Structure: see text] A 1,4-bis(phenyl)-1,4-dihydro[60]fullerene resulting from an efficient nucleophilic substitution has been obtained by reaction of a fullerene epoxide, C60O, with nucleophilic aromatic compounds in the presence of boron trifluoride etherate as a Lewis acid. 相似文献
998.
Matsuya T Otake K Tashiro S Hoshino N Katada M Okuyama T 《Analytical and bioanalytical chemistry》2006,385(5):797-806
We have developed a new time-resolved fluorometric (TRF) microarray detection system consisting of fluorescent NH2 nanosphere, TRF microarray detector and gamma-irradiated polystyrene chip. Using the TRF microarray detector, we detected 500 particles of the fluorescent nanosphere in one channel. Cross-talk fluorescence from the adjacent channels was little observed in the TRF microarray detector (<0.0004 %). The TRF microarray detection system was further applied for serum allergen-specific immunoglobulin E (IgE) multi-analyses. As a labeled tag antibody, an anti-human IgE Fab’ fragment-conjugated fluorescent nanosphere (Fab’ nanosphere) was prepared as described previously. As a chip surface appropriate for allergen immobilization, the polystyrene chip surface was modified by gamma irradiation. The immunoassay reactivity using the gamma-irradiated polystyrene chip was approximately 2.5-times improved compared with that of the non-treated polystyrene chip. Non-specific adsorption of the Fab’ nanosphere onto the gamma-irradiated polystyrene chip surface was very low level (<0.0009 %). In only 20 μl of serum, six allergen-specific IgEs could be simultaneously determined in one reaction well in fewer than 90 min. Good correlation curves were obtained between the microarray immunoassay and the CAP RAST fluoro-enzyme immunoassay (CAP/RAST FEIA) method (r>0.961). Reproducibility (CVs) of the microarray immunoassay was 8.6 % to 19.0 % (n=5). 相似文献
999.
A capillary-assembled microchip (CAs-CHIP), prepared by simply embedding square capillaries in a lattice polydimethylsiloxane
(PDMS) channel plate with the same channel dimensions as the outer dimensions of the square capillaries, has been used as
a diffusion-based pretreatment attachment in capillary electrophoresis (CE). Because the CAs-CHIPs employ square-section channels,
diffusion-based separation of small molecules from sample solutions containing proteins is possible by using the multilayer
flow formed in the square section channel. When a solution containing high-molecular-weight and low-molecular-weight species
makes contact with a buffer solution, the low-molecular-weight species, which have larger diffusion coefficients than the
high-molecular-weight species, can be collected in a buffer-solution phase. The collected solution containing the low-molecular-weight
species is introduced into the separation capillary to be analyzed by CE. This type of system can be used for CE analysis
in which pretreatment is required to remove proteins. In this work a fluorescently labeled protein and rhodamine-based molecules
were chosen as model species and a feasibility study was performed.
相似文献
1000.
Elaborating on Katzel's result, Zhai obtained a sharp short interval result for the number of ways of expressing a square-free integer as sums of two squares. In this note we view Zhai's decom- position as one by degree 1 prime ideals in the Gaussian field and extend Zhai's approach to a wider range of quadratic fields etc. 相似文献