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101.
Ogo S Miyamoto M Ide Y Sano T Sadakane M 《Dalton transactions (Cambridge, England : 2003)》2012,41(33):9901-9907
A new pathway for the preparation of mono-ruthenium (Ru)(iii)-substituted Keggin-type heteropolytungstates with an aqua ligand, [PW(11)O(39)Ru(iii)(H(2)O)](4-) (1a), [SiW(11)O(39)Ru(iii)(H(2)O)](5-) (1b) and [GeW(11)O(39)Ru(iii)(H(2)O)](5-) (1c), using [Ru(ii)(benzene)Cl(2)](2) as a Ru source was described. Compounds 1a-1c were prepared by reacting [XW(11)O(39)](n-) (X = P, Si and Ge) with [Ru(ii)(benzene)Cl(2)](2) under hydrothermal condition and were isolated as caesium salts. Ru(benzene)-supported heteropolytungstates, [PW(11)O(39){Ru(ii)(benzene)(H(2)O)}](5-) (2a), [SiW(11)O(39){Ru(ii)(benzene)(H(2)O)}](6-) (2b) and [GeW(11)O(39){Ru(ii)(benzene)(H(2)O)}](6-) (2c), were first produced in the reaction media, and then transformed to 1a, 1b and 1c, respectively, under hydrothermal conditions. Calcination of Ru(benzene)-supported heteropolytungstates, 2a, 2b and 2c, in the solid state produced mixtures of 1a, 1b and 1c with CO (carbon monoxide)-coordinated complexes, [PW(11)O(39)Ru(ii)(CO)](5-) (4a), [SiW(11)O(39)Ru(ii)(CO)](6-) (4b) and [GeW(11)O(39)Ru(ii)(CO)](6-) (4c), respectively. From comparison of their catalytic activities in water oxidation reaction, it was indicated that ruthenium should be incorporated in the heteropolytungstate in order to promote catalytic activity. 相似文献
102.
Xue-gang Chen Shinya Fujita Michitaka Furuya Moo Young Sohn 《Discrete Applied Mathematics》2012,160(4-5):488-493
A graph is said to be bicritical if the removal of any pair of vertices decreases the domination number of . For a bicritical graph with the domination number , we say that is -bicritical. Let denote the edge-connectivity of . In [2], Brigham et al. (2005) posed the following question: If is a connected bicritical graph, is it true that In this paper, we give a negative answer toward this question; namely, we give a construction of infinitely many connected -bicritical graphs with edge-connectivity for every integer . Furthermore, we give some sufficient conditions for a connected -bicritical graph to have . 相似文献
103.
Yamamoto M Nakaoka S Ura Y Kataoka Y 《Chemical communications (Cambridge, England)》2012,48(8):1165-1167
A palladium-catalyzed reaction of vinylarenes, allyl ethers, and 1,5-dienes with pinacol proceeded via a selective anti-Markovnikov nucleophilic attack to afford corresponding terminal acetals as major products. The bulkiness of pinacol was found to be critical in controlling the regioselectivity. 相似文献
104.
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106.
The geometrical arrangement of sites favourable for formic acid oxidation and the poison formation reaction is determined using low index platinum single crystal planes. For this determination, the least number of sites required for the reactions to occur, which was obtained in the study of electrocatalysis by adatoms, was used, that is three adjacent sites are required for formic acid oxidation and four adjacent sites are required for poison formation.The triplet of sites on a unit lattice of Pt (111) and that on a unit lattice of Pt (100) plane are equally very favourable for the main oxidation reaction, but that on a unit lattice of Pt (110) is not so favourable as those on the former two planes. The oxidation rate is more than one order of magnitude lower on the latter than on the former triplets.The poison formation reaction proceeds at a very high rate on the (100) and the (110) planes. The geometrical arrangement of four sites on a square unit lattice of the (100) plane and on a rectangular unit lattice of the (110) plane are favourable for the poison formation reaction, but that on a hexagonal unit lattice of the (111) plane is not so favourable as the former two. 相似文献
107.
108.
Shigeyuki Tasaka Hirokazu Tanabe Yoshiyuki Sasaki Toshiki Machida Mayumi Iino Akira Kiue Seiji Naito Michihiko Kuwano 《Journal of heterocyclic chemistry》1997,34(6):1763-1767
We have investigated 3-substituted-2-phenylimidazo[2,1-b]benzothiazole derivatives and herein we have discussed their pharmaceutical activities. We found that some 2-phenyl-5,6,7,8-tetrahydroimidazo[2,1-b]-benzothiazoles could overcome multidrug resistance for tumor cells. Among them, 2-phenyl-3-(N-methyl-3-piperidyl)carbonylammomiinomemyl-5,6,7,8-tetrahydVoimidazo[2,1-b]benzothiazole [N276-12] demonstrated the most potent activity for overcoming multidrug resistance. 相似文献
109.
Mayumi Takasu Hiroaki Wakabayashi Kyoji Furuta Hisashi Yamamoto 《Tetrahedron letters》1988,29(52):6943-6946
Achiral and chiral crowns complexed with potassium bases catalyze the Michael additions of enolates to cycloalkenones. 相似文献
110.