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91.
Yuji Naruse Atsushi Takamori Itsuki Nagasawa 《Phosphorus, sulfur, and silicon and the related elements》2020,195(7):523-525
AbstractWe previously designed and prepared the first molecules to exhibit observable CD spectra by n-σ* excitation, 2,6-dithiaspiro[3.3]heptane 2,6-dioxide. Spiro[3.3]heptane frameworks possess axial asymmetry due to puckering of 2 four-membered rings; the ring bonds are rich in p-character due to acute bond angles, which lowers the σ* energy levels. In contrast, the lone pairs are rich in s-character, which results in a good donor with conformational fixation. We expected that, instead of lone pairs as donating orbitals, the use of σ-electron-donating Si-Si bonds should result in UV absorption in the observable range (>180?nm), so that the Cotton effect could appear, at least partially, in that range. We designed 2,6-disilyl-2,6-disilaspiro[3.3]heptanes as models, and performed theoretical calculations to confirm our idea. 相似文献
92.
M. Ueshima K. Sano M. Ikeda K. Yoshino J. Okamura 《Research on Chemical Intermediates》1998,24(2):133-141
The selective catalytic oxidation (SCO) of ammonia to N2 was studied by using a series of noble metal-V2O5-WO3 catalysts supported on titania-silica (TS) prepared by coprecipitation method. In the V2O5-WO3 catalyst system, the use of TS as a support was very effective to enhance catalytic activity compared with TiO2 or SiO2 alone. The addition of a slight amount of Pd and Ir to V2O5-WO3/TS catalyst caused also remarkable enhancement of the catalytic activity without decreasing the selectivity to N2. The present catalysts provide remarkably high catalytic performance for SCO of ammonia to N2 under the practical reaction conditions for an industrial application. 相似文献
93.
Toru Tachihara Susumu Ishizaki Yoshiko Kurobayashi Hiroshi Tamura Youichi Ikemoto Atsushi Onuma Keisuke Yoshikawa Tetsuya Yanai Takeshi Kitahara 《Helvetica chimica acta》2003,86(2):274-279
All possible stereoisomers of imine derivatives 1 – 4 , which have the characteristic roast odor of seafood, were synthesized. As a result of odor evaluation of all isomers, we found that each isomer has a different and characteristic odor of roasted seafood. 相似文献
94.
Hiroshi Ikeda Takumi Sugiyama Akihiko Ueno 《Journal of inclusion phenomena and macrocyclic chemistry》2007,57(1-4):83-87
A new chemosensor for larger guests was prepared. The new chemosensor bears hydrophobic units at the primary hydroxy side
and a dansyl unit at the secondary hydroxy side of β-cyclodextrin. Due to the hydrophobic units, the new chemosensor is sensitive
to large or slender guests such as SDS and insensitive to 1-adamantanol, which is a good guest for the natural β-CD. 相似文献
95.
Yoshihisa Kurasawa Tomoyoshi Hosaka Kazue Ikeda Yuko Matsumoto Aiko Ishikura Atsushi Takada Ho Sik Kim Yoshihisa Okamoto 《Journal of heterocyclic chemistry》1994,31(2):527-533
The 3-(arylhydrazono)methyl-2-oxo-1,2-dihydroquinoxalines 9–11 were synthesized by the reaction of the quinoxalines 6–8 with various p-substituted benzenediazonium salts. Compounds 9–11 showed the tautomeric equilibria between the hydrazone imine A and diazenyl enamine B forms in dimethyl sulfoxide media. The substituent effect on the tautomer ratios of A to B was studied by the nmr spectroscopy to clarify that the presence of the ester group R2 on the hydrazone carbon and electron-donating p-substituent R1 on the side chain benzene ring exhibited a tendency to increase the ratios of the tautomer A . 相似文献
96.
97.
The synthetic procedures for spilanthol and trail-following pheromone for a southern subterranean termite were described. The syntheses heavily depend on the new diene synthesis using titanium reagent. 相似文献
98.
Mao-Peng Lin Haeng-Boo Kim Tomiki Ikeda Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》1992,30(11):2365-2369
Benzyl cation was detected by transient absorption spectroscopy with a spectroscopic multichannel analyzer on pulse excitation (fourth harmonic of Nd:YAG laser, 266 nm; 10 ns fwhm) of benzyl(4-hydroxyphenyl) methylsulfonium hexafluoroantimonate(BSS) in 1,2-dichloroethane (EDC). The benzyl cation was long-lived (lifetime, 59 ms) at room temperature and quenched by a vinyl ether compound. The formation of the benzyl cation as active species on photolysis of BSS is in contrast to the formation of Brønsted acids in other sulfonium salts so far reported. © 1992 John Wiley & Sons, Inc. 相似文献
99.
Kotaro Hidea Hiroshi Maezawa Atsushi Ito Katsumi Kobayashi Yoshiya Furusawa Takashi Ito 《Photochemistry and photobiology》1986,44(3):417-419
The spectral throughput of a vacuum-ultraviolet irradiation system at the SOR-RING facility was examined with various combinations of aluminum-and gold-coated optical elements in a 2.2-m modified Wadsworth monochromator. We found that the optimum was a combination of an aluminum-coated collimating mirror, concave grating, and plane deflecting mirror, and a combination of a gold-coated collimating mirror, concave grating and an aluminum-coated plane deflecting mirror in the wavelength regions 190-110 nm and 110-50 nm, respectively. 相似文献
100.
It has been shown by a series of experiments on 5-alkyl, 5-halo-, and other 5-substituted 1-naphthol derivatives that the product ratio of the ortho- and para-naphthoquinones formed on oxidation with Fremy's salt is controlled by the bulkiness of the C5-substituent. 相似文献