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521.
Reactions of ruthenium complexes having 2-pyridinecarboxylato and 2,2'-bipyridine ligands with sodium azide in alcohol afforded nitrido-bridged diruthenium complexes, [{Ru(OR)(pyca)(bpy)}2(mu-N)](+) (R = CH3, C2H5). Diruthenium complexes showed diamagnetic properties, a linear Ru-N-Ru coordination configuration, and two irreversible oxidation waves and two reversible reduction waves. 相似文献
522.
Hydrodynamic control of droplet division in bifurcating microchannel and its application to particle synthesis 总被引:1,自引:0,他引:1
Yamada M Doi S Maenaka H Yasuda M Seki M 《Journal of colloid and interface science》2008,321(2):401-407
We describe herein a microfluidic system for active and precise control of droplet division at a bifurcation point in a microchannel. Water-in-oil or oil-in-water droplets, which were initially formed at a T-junction, were introduced into the bifurcation point, and then divided into two daughter droplets. By continuously introducing 'tuning flow' into the downstream of one of the branch channels, and by controlling the flow rates distributed into the two branch channels, the sizes of the daughter droplets could be precisely tuned. The ratio of the volumetric flow rates into the branch channels was estimated by regarding the microchannel network as a resistive circuit. In addition, we performed synthesis of monodispersed polymer particles with controlled sizes utilizing the presented system. The ability to hydrodynamically control the droplet sizes will open new possibilities not only for producing useful emulsions, but also for conducting controlled chemical and biochemical reactions in a confined space. 相似文献
523.
Ng YH Ikeda S Harada T Morita Y Matsumura M 《Chemical communications (Cambridge, England)》2008,(27):3181-3183
Platinum nanoparticles embedded in a hollow porous carbon shell prepared by a photocatalytic reaction acted as a reusable catalyst for the aerobic oxidation of alcohols under atmospheric pressure of oxygen in water. 相似文献
524.
Oshima T Asahara H Koizumi T Miyamoto S 《Chemical communications (Cambridge, England)》2008,(15):1804-1806
The acid-induced reaction of bis(p-chlorophenyl)homobenzoquinone epoxide gave the dual ipso/ortho intramolecular S(E)2-Ar products associated with pi-aryl participated oxirane ring opening, whereas bis(p-tolyl)- and diphenyl-substituted homologues provided only the ortho products. 相似文献
525.
A kinetic study has been made of the BF(3)-mediated ring opening of two rigid conformers (alpha and beta) of m- and p-dimethyl-substituted homobenzoquinone epoxides spiro-linked with a twist-boat dibenzocycloheptene ring as compared with the conformationally mobile epoxides bearing diphenyl groups. The rates of the regioselective ring opening were dependent on the topological alignment of the dibenzocycloheptene ring as well as the substitution pattern of the quinone dimethyl groups, indicating pi-aryl participated orbital interaction with the vacant Walsh orbital of the oxirane ring. 相似文献
526.
Glycosyl boranophosphate triesters were synthesized via a boranophosphorylation of reducing sugars. The usefulness of the resultant glycosyl boranophosphates as versatile chemically stable precursors of various glycosyl phosphate derivatives is demonstrated. 相似文献
527.
The lipase-catalyzed ROP of molecularly pure cyclic oligomers with a definite degree of oligomerization is analyzed with respect to the molecular weights of the resulting polymers and certain kinetic parameters of the enzymatic reaction. Cyclic BA dimers, trimers, and tetramers polymerize faster than the equivalent monomer; however, the latter produces PBA of significantly higher molecular weight. The reason is that the ring opening of the cyclic monomer is slow, leading to a lower initiator concentration than that produced by the cyclic BA dimer and trimer. Similarly, the cyclic BS dimer produces PBS of higher molecular weight than that obtained from the cyclic BS trimer. 相似文献
528.
Matsumura T Ohoyama H Watanabe D Yasuda K Kasai T 《The journal of physical chemistry. A》2007,111(16):3069-3073
Atomic orbital alignment effect was observed for the CN (B2Sigma+) formation in the reaction of oriented Ar (3P2) with CH3CN (CD3CN). The relative cross-sections for each magnetic MJ' substrate in collision frame sigmaH|MJ'| for CH3CN and sigmaD|MJ'| for CD3CN, were determined to be sigmaH0:sigmaH|1|:sigmaH|2|:sigmaD0:sigmaD|1|:sigmaD|2| = 1.00:0.81:0.84:2.01:1.92:1.87. A significant atomic orbital alignment effect was observed. In addition, a notable deuterium isotope effect was observed on both the cross-section and the atomic orbital alignment effect. 相似文献
529.
Kurashige Y Nakajima T Kurashige S Hirao K Nishikitani Y 《The journal of physical chemistry. A》2007,111(25):5544-5548
Using time-dependent density functional theory (TD-DFT), configuration interaction single (CIS) method, and approximate coupled cluster singles and doubles (CC2) method, we investigated the absorption spectra of coumarin derivative dyes (C343, NKX-2388, NKX-2311, NKX-2586, and NKX-2677), which have been synthesized for efficient dye-sensitized solar cells. The CC2 calculations are found in good agreement with the experimental results except for the smallest coumarin dye (C343). TD-DFT underestimates the vertical excitation energy of the larger coumarin dyes (NKX-2586 and -2677). Solvents (methanol) are found to induce a red shift of the vertical excitation energies, and their effects on the molecular geometry and the electronic structure are examined in detail. The deprotonated form of coumarin is also investigated, where a blue shift of the vertical excitation energies is observed. 相似文献
530.
Watanabe D Ohoyama H Matsumura T Kasai T 《The journal of physical chemistry. A》2007,111(30):6915-6919
Atomic alignment effect for the CF3* formation in the oriented Ar (3P2, MJ = 2) + CF3H reaction has been investigated at different two CF3H beam conditions: effusive and supersonic beams. The chemiluminescence intensity of CF3* was measured as a function of the magnetic orientation field direction in the collision frame. A significant contribution of rank 4 moment was recognized. The cross-section for each magnetic M'(J) substate in the collision frame, sigma|M'(J)|, was determined to be sigma(|M'(J)|=0):sigma(|M'(J)|=1):sigma(|M'(J)|=2) = 1.00:0.84 +/- 0.02:0.88 +/- 0.02 for the effusive CF3H beam condition. The atomic alignment effect was found to significantly depend on the CF3H beam condition. For the supersonic beam condition, sigma(|M'(J)|=0&1) was changed to be smaller than sigma(|M'(J)|=2). 相似文献