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21.
Kenji Yokota Hideo Tomioka Teruyuki Ono Fumimasa Kuno 《Journal of polymer science. Part A, Polymer chemistry》1972,10(5):1335-1343
The sensitization effect of tertiary amines on the photopolymerization of methyl methacrylate was studied. N,N-Dimethylbenzylamine, triethylamine, and N,N-dimethylaniline increased the rate of polymerization in this order, but pyridine did not show any effect. A free-radical mechanism was confirmed by the tacticity of polymer, the retarding effect of hydroquinone, and the copolymer composition with styrene. On the basis of the detailed kinetics of the sensitized polymerization and the ultraviolet spectra of the reaction mixtures, a sensitization mechanism is proposed, in which the excited monomer and the amine form a complex and generate an initiating radical. 相似文献
22.
Rikuhei Tanikaga Yoshimasa MatsumotoMaki Sakaguchi Yohei KoyamaKentaro Ono 《Tetrahedron letters》2003,44(35):6781-6783
Lipase-mediated acetylations of trans- and cis-2-substituted cyclohexanols gave the corresponding (1R)-cyclohexyl acetates and (1S)-cyclohexanols in high yields and ee, but c-4-tert-butyl-c-2-ethenyl-r-1-cyclohexanol was unreactive owing to the steric interaction between the axial OH group and the axial H atoms at the 3- and 5-positions. In the cis-isomer the OH group occupies an equatorial position to bind to the lipase, and less bulky axial alkenyl and alkynyl groups might not so much prevent acetylations than an alkyl group. 相似文献
23.
Atsunori Matsuda Tatsuo Matoda Toshihiro Kogure Kiyoharu Tadanaga Tsutomu Minami Masahiro Tatsumisago 《Journal of Sol-Gel Science and Technology》2004,31(1-3):229-233
Titania nanosheet-precipitated coatings have been prepared by treating SiO2-TiO2 gel films on glass substrates with hot water at 90°C under vibration. Longitudinal vibrations at about 6 Hz during the treatment enhanced the formation of titania nanosheet. The titania nanosheet consisted of several layers with a spacing of about 0.6 nm and was identified as hydrated titania with a lepidocrocite-type structure. The morphology of the titania nanosheet-precipitated coatings is probably achieved by lowering of the concentration of hydrolyzed titania species at the surface due to rapid water flow driven by the vibrations. The coatings were transparent in the visible range and showed high photocatalytic activity and antifogging property. 相似文献
24.
S. Tamai J. Kamada T. Ono T. Kuroki K. Goto A. Yamaguchi 《Journal of polymer science. Part A, Polymer chemistry》2002,40(3):423-428
Polyimide containing an indan unit and alkyl moiety with a high molecular weight was prepared from 5,7‐diamino‐1,1,4,6‐tetramethylindan and 3,3′,4,4′‐benzophenone tetracarboxylic dianhydride. This polyimide was amorphous and soluble in common organic solvents, such as tetrahydrofuran, chloroform, and cyclopentanone. Thermogravimetry of the polyimide showed good thermal stability, indicating that a 10% weight loss of the polyimide was observed at 500 °C in nitrogen. The glass‐transition temperature of the polyimide was not observed by DSC measurement between room temperature and 400 °C at a heating rate of 10 °C/min (Apparatus: DSC3100 MAC Science Co., Ltd.). Transparency of the polyimide at 365 nm was 80%. The polyimide acted as a photosensitive resist of negative type by UV radiation. The resist had a sensitivity of 31 mJ/cm2 and a contrast of 2.3 when it was developed with cyclopentanone at room temperature. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 423–428, 2002 相似文献
25.
A. Ono 《Chromatographia》1980,13(12):752-754
Summary Xylenol isomers can be resolved on most polyols (sugars or sugar alcohols) and polyethers (polyethylene glycol or polypropylene glycol) with hydrogen-bonding interaction. They are separated on vinical polyols which have more hydroxy hydrogen than tetrol, and even on vicinal triol when its hydroxy hydrogen is acidic (stronger proton donor). The stronger is the hydrogen bonding interaction between xylenols and the liquid phase, the better is the separation of 2,4- and 2,5-xylenol, and the poorer the separation of 2,4-and 2,3-xylenol. 相似文献
26.
The negative chemical ionization mass spectra of representative perfluorinated alkanes, cycloalkanes, ethers and tertiary amines have been examined, using Ar at about 0.5 torr as the reagent gas. The compounds chosen are typical of those under study as components of fluorochemical emulsion blood substitutes. Many such PFC's, particularly those with cyclic or branched structures, give intense molecular ions; most give simple spectra with a few major fragment ions at high mass, in marked contrast to the EI spectra which are dominated by m/e 69 (CF3+) and 131 (C3F5+) of no value for structure elucidation. NCI-GC/MS is more sensitive than conventional EI-GC/MS and promises to be more generally useful for structure determination. Specific examples from the various classes will be presented, and their NCI and EI mass spectra compared. 相似文献
27.
Ono K Yoshida A Saito N Fujishima T Honzawa S Suhara Y Kishimoto S Sugiura T Waku K Takayama H Kittaka A 《The Journal of organic chemistry》2003,68(19):7407-7415
Six novel 2-substituted analogues of 1alpha,25-dihydroxy-19-norvitamin D(3), 6a,b-8a,b, were efficiently synthesized utilizing (-)-quinic acid as the A-ring precursor. The C2-modified A-rings were prepared as 4-alkylated (3R,5R)-3,5-dihydroxycyclohexanones 12-15 from (-)-quinic acid based on radical allylation at the C4 position of methyl (-)-quinicate. The new type of the CD-ring coupling partner 23 was synthesized from 25-hydroxy Grundmann's ketone 19 to apply to the modified Julia olefination to construct a diene unit between the A-ring and the CD-ring. The coupling yields, including a deprotection step, were 47-62%. After the separation of the diastereomers based on C2 stereochemistry, the structure (2alpha or 2beta) was determined by (1)H NMR experiments and compared to DeLuca's 2-methyl- and 2-ethyl-1alpha,25-dihydroxy-19-norvitamin D(3). Thus, the synthesized 2alpha-(3-hydroxypropyl)-1alpha,25-dihydroxy-19-norvitamin D(3) (8a) showed almost the same potency in binding to the bovine thymus vitamin D receptor (VDR) as the natural hormone 1, while its beta-isomer 8b had only a 3% affinity. Both 2alpha-allyl- and 2alpha-propyl-1alpha,25-dihydroxy-19-norvitamin D(3) (6a and 7a) and their 2beta-analogues (6b and 7b) possessed a weak affinity for the VDR. The strong VDR ligand 8a was ca. 36-fold more potent in induction of HL-60 cell differentiation than 1, and interestingly, even the weaker ligand 8b showed a 6.7-fold higher potency in the cell differentiation activity than that of 1. 相似文献
28.
Moisture of several ppm in hydrogen chloride gas has been accurately determined by a new method using the Karl Fischer reagent, which hitherto had a limitation in accuracy because of a partial reaction with hydrogen chloride when direct titration was employed.The moisture in the sample gas was collected in a cold trap kept at about ?80 °C while the hydrogen chloride gas passed through and the frozen moisture was dissolved by pyridine-methanol (1:1) solvent. a KF Reagent of factoe: 0.35 mg H2O/ml.Titration by the Karl Fischer reagent having the equivalency factor of, e.g., 0.5 mg H2O/ml was carried out and the concentration of the moisture was calculated from the sample volume used. 相似文献
29.
The nitro group in tertiary or secondary aliphatic nitro compounds is replaced by hydrogen or deuterium on treatment with tributyltin hydride or tributyltin deuteride, respectively. 相似文献
30.
Yasushi Mizobe Reiko Ono Yasuzo Uchida Masanobu Hidai Meguru Tezuka Suehiro Moue Atsuhiko Tsuchiya 《Journal of organometallic chemistry》1980,204(3):377-385
Diazoalkane complexes of type [MF(NNCRR′)(dpe)2][BF4] (M = Mo or W; dpe = Ph2PCH2CH2PPh2), which are easily derived from bis(dinitrogen) complexes [M(N2)2(dpe)2], undergo consecutive one- and two-electron oxidations and reductions under voltammetric conditions at a platinum electrode. The ESR spectra of the species generated by the controlled potential electrolysis show that primary oxidation occurred on the metal atom (M = Mo) and reduction on the two nitrogen atoms in the diazoalkane ligands (M = Mo or W). 相似文献