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351.
Nakamura M Okaue T Takada T Yamana K 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(1):196-201
π-Stacked naphthalenediimide (NDI) arrays are of interest as charge-transport materials. We have designed and synthesized an NDI derivative with two Zn(II)-cyclens that act as receptors for the thymine base in DNA. UV/Vis and CD spectroscopy, gel filtration, and molecular-modeling studies have shown that the bis(Zn(II)-cyclen)-NDI can be assembled in the presence of oligo-dT to form π-stacked NDI arrays. The assembly of the NDI arrays was found to be dependent on the length of the oligo-dT and the temperature. The NDI-oligo-dT assembly on a gold substrate exhibits photocurrent responses due to electron transfer through the π-stacked array. 相似文献
352.
Matsunaga H Tokuda R Nakajima M Ishizuka T 《Chemical & pharmaceutical bulletin》2010,58(10):1419-1421
The preparation of a new class of "roofed" β-iminodisulfides from sterically congested, conformationally rigid chiral 2-thiazolidinones is described. A functional survey of palladium-catalyzed asymmetric allylic alkylation of 1,3-diphenyl-2-propenyl acetate with dimethyl malonate proved that symmetrical "roofed" β-iminodisulfides are efficient chiral ligands, showing enantioselectivity opposite that associated with chiral "roofed" β-iminothioether ligands. 相似文献
353.
We investigate the equivariant cohomology of the natural torus action on a K-contact manifold and its relation to the topology of the Reeb flow. Using the contact moment map, we show that the equivariant cohomology of this action is Cohen–Macaulay, the natural substitute of equivariant formality for torus actions without fixed points. As a consequence, generic components of the contact moment map are perfect Morse-Bott functions for the basic cohomology of the orbit foliation ${{\mathcal F}}$ of the Reeb flow. Assuming that the closed Reeb orbits are isolated, we show that the basic cohomology of ${{\mathcal F}}$ vanishes in odd degrees, and that its dimension equals the number of closed Reeb orbits. We characterize K-contact manifolds with minimal number of closed Reeb orbits as real cohomology spheres. We also prove a GKM-type theorem for K-contact manifolds which allows to calculate the equivariant cohomology algebra under the nonisolated GKM condition. 相似文献
354.
Copper-catalyzed oxidative coupling of arylboronic acids with imidazoles in water was realized by using an amphiphilic surfactant. By choosing an appropriate surfactant, reactions of a variety of arylboronic acids proceeded smoothly under mild and base-free conditions, providing an efficient, practical, and greener method for the synthesis of N-arylimidazoles. 相似文献
355.
DNA oligomers possessing a 2-nitrobenzyl (NB) protected thiol group have been prepared. The photo-remove of the NB to generate a free thiol group in DNA has been analyzed by using reverse-phase HPLC and denaturing gel electrophoresis. The photo-triggered generation of the thiol function in DNA was applicable in the light-initiated ligation of thiol-modified DNA oligomers and Au–DNA conjugation. 相似文献
356.
357.
Tadao Aoki 《Journal of Quantitative Spectroscopy & Radiative Transfer》1980,24(3):191-202
A simple but accurate formula is given that describes the characteristics of the transmission function of gaseous absorption bands which are not well described by the Mayer-Goody random band model (e.g. the effect of the difference of line-intensity distribution between wavenumber intervals). The temperature dependence of the transmission function is also well described.The parameters for our model have been determined for infrared bands of water vapor and carbon dioxide by fitting values of transmittance calculated from line parameter data of McClatchey et al. The results have been compared with experimental measurements. 相似文献
358.
Haruhiko Furukawa Tadao Kanzaki Takashi Katsura 《Journal of Electron Spectroscopy and Related Phenomena》1985,36(1):1-10
The X-ray photoelectron spectra of Mo 3d electrons (232.4–232.9 and 229.4–229.6 eV) for Mo-bearing ferrites have suggested that molybdenum ions are in the 4+ valence state on the lattice points in the spinel structure. The XPS data for Mo 3d and Fe 2p electrons combined with the Mössbauer data at room temperature suggest that Fe2MoO4 takes a valence state (Fe2+)tet[Fe2+Mo4+]octO4. 相似文献
359.
360.
Tadao Kotaka Nobuo Donkai Hiroshi Inagaki 《Journal of Polymer Science.Polymer Physics》1971,9(8):1379-1397
The sedimentation-equilibrium method is extended to treat nonideal solutions of heterogeneous macromolecules. The solute is assumed to be heterogeneous not only in molecular weight but also in other quantities such as partial specific volume, second virial coefficient and specific refractive increment. General expressions for various observable molecular weights, especially for weight-average, z-average, and number-average molecular weights, are derived. Their dependences on sedimentation parameter and solute concentration are discussed in detail. For the extrapolation of observable molecular weights, giving a type of weight-average, and z-average, to infinite dilution to estimate the molecular weight and the second virial coefficient, average concentration is superior as a concentration variable to original concentration. The plots of observable molecular weight versus average concentration are usually less influenced by the choice of the sedimentation parameter, especially of rotor speed. The general expressions are applied to a few special cases; monodisperse polymer, polydisperse homologous polymer, and polymer blend. The results are compared with experiments on a monodisperse, polystyrene, a polydisperse poly(methyl methacrylate), and a mixture of the two polymers, all in 2-butanone at 25°C. The agreement between the theory and experiments is satisfactory. 相似文献