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61.
Ken Sakai Yoshinobu Miyabe 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(2):m69-m72
In the title compound, [Ru(C10H8N2)2(C12H8N2)][Pt(CN)4], cations and anions alternate along the a axis to afford a one‐dimensional network. The one‐dimensional character arises from the π–π stacking as well as from the electrostatic interactions formed between the phen (1,10‐phenanthroline) and [Pt(CN)4]2− units. Two adjacent one‐dimensional chains form further stacks based on the π–π stacking interactions between the phen moieties, where the interplanar spacing is 3.50 (1) Å. 相似文献
62.
The combination of series of measurements of band broadening made with the peak parking (PP) method, using successively an open capillary tube and a HPLC column, gives a convenient procedure for the measurement of the molecular diffusivity (Dm) of compounds in solutions, of their axial dispersion coefficient (Dax,m) in chromatographic columns, and of the tortuosity or obstructive factor of the column bed. The molecular diffusivity measured for benzene in methanol was in excellent agreement with literature data. The ratio of the axial dispersion coefficient to this diffusivity gives the obstructive factor (γm) of the packed bed, which was 0.74 for the column used. The values of Dm in other solutions were obtained from the Dax,m values measured by the PP method, by correcting the Dax,m values with the γm value. The Dm values determined by this method were in good agreement with those previously reported or estimated using literature correlations. These results showed that the PP method is effective for the experimental measurement of Dm. 相似文献
63.
The use of inorganic semiconductor particles such as titanium dioxide(TiO_2) has received relatively less attention in organic chemistry, although semiconductor particles have been widely used as a single electron transfer photocatalyst in waterpurification, air-cleaning, and self-cleaning. In recent years, the photocatalysis on semiconductor particles has become an active area of research even in organic chemistry, since the heterogeneous semiconductor photocatalysis leads to the unique redox organic reactions. In an early stage, the semiconductor photocatalysis was applied to the oxidation of organic molecules.Semiconductor particles have also the potential to induce the reductive chemical transformations in the absence of oxygen(O_2),by using the suitable sacrificial hole scavenger. In this review, we summarize the representative examples of the reductive and oxidative organic reactions using semiconductor particles and the recent applications to the stereoselective reactions. 相似文献
64.
Takao Tsuda Mahoro Hisanaga Takanori Inagaki Shinya Kitagawa Kanji Miyabe 《Analytical sciences》2004,20(7):1061-1064
A new type of fiber adsorbent attached with silica microparticles was prepared. The silica microparticles were formed by the polymerization of silica oligomers on glass fibers, which were woven into a glass filter. The surface of the silica microparticles was chemically modified by bonding C18-ligands. SEM images indicated that the diameter of the uniform and spherical silica microparticles fixed on glass fibers was on the order of micrometers. It was confirmed that the glass filter adsorbent was effective for the adsorptive removal of toluene of low concentrations. 相似文献
65.
66.
Mikihiko Saito Tamano Ushijima Kazumi Sasamoto Kenshi Yakata Yosuke Ohkura Keiyu Ueno 《Analytica chimica acta》1995,300(1-3):243-251
The new acid hydrazides, 2-(5-hydrazinocarbonyl-2-thienyl)-5,6-methylenedioxybenzofuran (TMBH) and 2-(5-hydrazin-ocarbonyl-2-furyl)-5, 6-methylenedioxybenzofuran (FMBH), were synthesized as precolumn fluorescence derivatisation reagents for carboxylic acids in liquid chromatography. These compounds readily react with carboxylic acids in the presence of a coupling reagent under mild conditions in aqueous solution to give fluorescent derivatives. The detection limits of lauric acid were both 0.1 pmol per 10 μl injection volume at a signal-to-noise ratio of 3. The methods in which these compounds are used were applied to the assay of a standard mixture of prostaglandins (25 μM) and prostaglandins in a human seminal fluid. 相似文献
67.
Stereocontrol in radical reactions of oxime ether anchored to polymer support was studied. Highly diastereoselective solid-phase radical reaction was achieved by using triethylborane and diethylzinc as a radical initiator at low reaction temperature, providing a novel method for the synthesis of the alpha-amino acid derivatives with excellent diastereoselectivities. 相似文献
68.
Novel intermolecular carbon radical addition to a nitrone: asymmetric synthesis of alpha-amino acids
Ueda M Miyabe H Teramachi M Miyata O Naito T 《Chemical communications (Cambridge, England)》2003,(3):426-427
A nitrone was used as a synthetically useful radical acceptor in carbon-carbon bond-forming radical reactions; the intermolecular addition of alkyl radicals to chiral glyoxylic nitrone was studied; a high degree of stereocontrol in radical addition to glyoxylic nitrone was achieved to provide a new method for asymmetric synthesis of alpha-amino acids. 相似文献
69.
The diastereoselective alkyl radical addition to chiral oxime ethers was studied with a view to preparing enantiomerically pure alpha,beta-dialkyl-beta-amino acid derivatives. The phase transfer-catalyzed alkylation of Oppolzer's camphorsultam derivative of oxime ether proceeded smoothly to give the alkylated N-(beta-oximino)acyl derivatives. In the presence of BF3.OEt2, radical addition to the oxime ethers proceeded using triethylborane as the radical initiator to give alpha,beta-dialkyl-beta-amino acid derivatives with excellent diastereoselectivity. 相似文献
70.
Factors affecting the near-UV induced reaction of calf thymus DNA in the presence of 8-methoxypsoralen were examined. DNA became more renaturable with increasing concentration of 8-methoxypsoralen and fluence. Existence of paramagnetic ions, Mn2+, Co2+, or Ni2+, largely repressed the photoreaction. It was ascertained that the highest renaturability was attained by the illumination with light between 310 and 345 nm. 相似文献