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21.
Tsuneyoshi Tominaga 《Journal of fluorine chemistry》2004,125(1):67-71
Synthetic routes for α-trifluoromethylated carbonyl compounds based on the aldol reaction of silylenol ether and the palladium(0) catalyzed reaction using by 4,4,4-trifluorobutan-2-one are described. 相似文献
22.
Tominaga Keii Yoshiharu Doi Hiromu Kobayashi 《Journal of polymer science. Part A, Polymer chemistry》1973,11(8):1881-1888
Mass transfer which affects the rate of propylene polymerization with titanium trichloride–triethylaluminum, has been evaluated by use of a new method developed for this heterogeneous reaction. The polymerization was carried out with the usual flask reactor equipped with a paddle stirrer; the rate of gas absorption into the polymerization slurry was proportional to stirring speed and the reciprocal of the total amount of polymers produced. It has been confirmed that the polymerization rate separated from the absorption rate is purely kinetic (propagation), and an effective physical process, such as monomer transfer through a polymer film covering the catalyst surface, no longer exists. 相似文献
23.
The chelating behavior of a new resin prepared by polycondensation of N-(o-hydroxybenzyl) iminodiacetic acid (o-HDA) with phenol and formaldehyde, is compared with that of the monomer, with p-HDA resin and p-HDA monomer, and with Chelex-100. The order of chelate stability for the o-HDA resin is Cu(II) > Ni(II) > Zn(II) > Co(II). An unusually high stability of the o-HDA and o-HDA resin iron(III) chelates in acidic solution is attributed to the participation of the o-hydroxyl group in the coordination process. 相似文献
24.
Yoshinori Tominaga Jiann-Kuan Luo Lyle W. Castle Raymond N. Castle 《Journal of heterocyclic chemistry》1993,30(1):267-273
The synthesis of the novel pyrazolo[4′,3′:5,6]pyrido[2,3-d]pyridazine ring system and some of its derivatives has been accomplished such as 4-amino-1-phenyl-5,8-dioxo-, 4-amino-5,8-dioxo-, 1-phenyl-5,8-dioxo-, 5,8-dioxo-, 5,8-dichloro-1-phenyl-, 5-ethoxy-1-phenyl- and 8-ethoxy-1-phenylpyrazolo[4′,3′:5,6]pyrido[2,3-d]pyrid-azines. 相似文献
25.
S. R. Sarkar K. Une Y. Tominaga 《Journal of Radioanalytical and Nuclear Chemistry》1997,220(2):155-159
This work reports the determination of oxygen to uranium (O/U) ratio in irradiated UO2+x fuel pellet of burnup of ca. 34 GWd/t by controlled potential coulometry. The method is based on the dissolution of the nuclear fuel in strong phosphoric acid (SPA) at 180–190 °C under an inert atmosphere. After dissolution, 8% sulphuric acid is added in order to obtain a 20% SPA in 8% sulphuric acid. A controlled potential coulometric determination of uranium(VI) is carried out at ?0.60V vs. ferri-ferrocyanide. The uranium(IV) contained in an aliquot of the fuel solution is oxidised to uranium(VI) with cerium(IV) sulphate, and the total uranium content is then determined by coulometry. Optimum experimental conditions have been established using simulated irradiated fuel solution containing various fission products which include cerium, tellurium, palladium, ruthenium, molybdenum and zirconium. Interference of the fission products and the possible removal of their interferences by preelectrolysis at +0.5 V vs. saturated calomel electrode (SCE) have been investigated. The accuracy of the coulometric method is confimed by polarographic measurement using several unirradiated UO2+x fuel of known stoichiometry. 相似文献
26.
The UV-induced photochemical reactions of pentacarbonyliron with ethene in a low temperature nitrogen matrix were studied by means of the Mössbauer technique. Fe/CO/4/C2H4/ was produced by UV-irradiation of penfacarbonyliron in close proximity to ethene molecules in a pure ethene matrix, or a homogeneous cocondensed matrix. The other products were obtained via thermal reactions with ethene of Fe/CO/4 trapped in stratified matrices. 相似文献
27.
Sumitra Tavornvipas Hidetoshi Arima Fumitoshi Hirayama Kaneto Uekama Toshihiro Ishiguro Masahide Oka Kenichi Hamayasu Hitoshi Hashimoto 《Journal of inclusion phenomena and macrocyclic chemistry》2002,44(1-4):391-394
Some physicochemical and biological properties of a new branched cyclodextrin, 6-O--(4-O--d-glucuronyl)-d-glucosyl--cyclodextrin GUG--CyD) were investigated. Further, theinteraction of GUG--CyD with several drugs was studied by the solubility and spectroscopic methods, and compared with those of parent -CyD and 6-O--maltosyl--CyD(2--CyD).The hemolytic activity of GUG--CyD on rabbit erythrocytes was lower than those of -CyD and 2--CyD. GUG--CyD and 2--CyD showed negligible cytotoxicity on Caco-2 cells up to at least 0.1 M. The inclusion ability of GUG--CyD to neutral and acidic drugs was comparable to or slightly smaller than those of -CyD and 2--CyD, probably because of a steric hindrance of the branched sugar. On the other hand, GUG--CyD showed greater affinity for the basic drugs, compared with -CyD and 2--CyD, owing to the electrostatic interaction of its carboxylate anion with positive charge of basic drugs. Thus GUG--CyD may be useful as a safe solubilizing agent particularly for basic drugs. 相似文献
28.
29.
Y. Yamada K. Onaka C. Obayashi H. Sato T. Tominaga 《Journal of Radioanalytical and Nuclear Chemistry》1995,199(6):477-492
Mössbauer parameters of tin compounds, Sn(CH3)nCl4–n (n=0, 1, 2, 3, 4), isolated in low temperature matrices are correlated with electronic properties at the tin nuclei obtained by molecular orbital calculations. The Mössbauer isomer shift and quadrupole splitting show good correlation with electron density and electric field gradient estimated by molecular orbital calculations, respectively. Structures of novel species (Sn(CH3)2CH2 and [Sn(CH3)2CH2]2) produced via photodissociation of Sn(CH3)4 in low temperature matrices were estimated by means of molecular orbital calculations as compared with Mössbauer parameters. 相似文献
30.
Yoshinori Tominaga Milton L. Lee Raymond N. Castle 《Journal of heterocyclic chemistry》1981,18(5):977-979
The cyclization of 2-acetonylthionaphthalene, prepared from 2-mercaptonaphthalene (1) and chloro-acetone in the presence of sodium hydroxide, with polyphosphoric acid gave 1-methylnaphtho[2,1-b]thiophene (4) in 64% overall yield from 1. By bromination with N-bromosuccinimide, 4 was converted in 40% yield into l-bromomethylnaphtho[2,1-b]thiophene (8) . Treatment of 8 with potassium cyanide in a phase-transfer medium gave l-cyanomethylnaphtho[2,1-b]thiophene (10) in good yield. Compound 10 was reduced to the corresponding aldehyde 11 and then cyclized with polyphosphoric acid to phenaleno[l,9-bc]thiophene (12) in 24% overall yield from 10. 相似文献