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991.
T. Ishikawa und A. Teramoto 《Colloid and polymer science》1978,256(4):404
Ohne Zusammenfassung 相似文献
992.
The electronic absorption spectra of four monosubstituted naphthalenes with an electron-accepting group, 1- and 2-naphthonitriles and 1- and 2-naphthaldehydes, have been investigated by means of configuration analysis with particular attention to the dependence of spectra on the position of substitution. The results of molecular orbital calculations based on the Pariser-Parr-Pople method were analyzed in terms of locally excited states and charge-transfer configurations. The characteristic changes in location of the Lb, La, and Bb bands caused by the substitution at 1- or 2-position are adequately explained by the analysis for monosubstituted naphthalenes with an electron-accepting group as well as for those with an electron-donating group. The results of the present configuration analysis for naphthalene derivatives with an electron-accepting group are compared with the results for those with an electron-donating group. 相似文献
993.
994.
We present simultaneous imaging of TiO2(110)-(1 x 1) and - (1 x 2) using noncontact atomic force microscopy (NC-AFM) and scanning tunneling microscopy (STM). The surface topography was imaged under NC-AFM feedback, while the surface electronic states were imaged by STM. The image contrasts of NC-AFM and STM were antiphase in (1 x 1) and in phase in (1 x 2). The uppermost oxygen and Ti atoms underneath were, respectively, imaged by NC-AFM and STM. The NC-AFM image contrast was close to the true surface topography in (1 x 2), but reduced in (1 x 1). 相似文献
995.
The reaction of ene-imine with Cp(2)ZrBu(2) was carried out. When a crude imine, which was prepared from ene-aldehyde and primary amine in the presence of MgSO(4), was treated with Cp(2)ZrBu(2) at room temperature overnight, cyclopentane derivative having trans-substituents was obtained in high yield along with a small amount of cyclopentane derivative having cis-substituents. Presumably, cis-zirconacycle is a thermodynamic product. Reactions using various ene-imines were carried out. In the case of ene-imine prepared from ene-aldehyde and (t)BuNH(2), only cyclopentane having cis-substituents was produced. In this reaction, chiral amine was used, and diastereoselective cyclization of ene-imine was carried out. As a result, cyclopentane derivative having cis-substituents was obtained in an optically active form after hydrogenolysis of the cyclized compound. 相似文献
996.
Ishikawa T Ishii H Shimizu K Nakao H Urano J Kudo T Saito S 《The Journal of organic chemistry》2004,69(23):8133-8135
Diastereoselective total synthesis of isocarbacyclin, which features a fused bicyclic key intermediate available from l-ascorbic acid, is described. The key intermediate was prepared in multigram quantities by the Pauson-Khand reaction of l-ascorbic acid-based (R)-4,4-diallyl-2,2-dimethyl-5-(trimethylsilyl)ethynyl-1,3-dioxolane (3), discriminating diastereotopic groups and faces of the geminal allyl substituents. 相似文献
997.
Direct conversion of epoxides to aziridines was achieved with guanidines as a nitrogen source. Stereochemical inversion at the chiral centers of epoxides was observed without loss of optical purity. 相似文献
998.
999.
Simple sulfonamide and amide derivatives of tris(2-aminoethyl)amine (Tren) are known to promote the translocation or flip-flop of phosphatidylcholine, but not phosphatidylserine, across bilayer membranes. This paper describes the synthesis of a 300-member, spatially encoded library of Tren derivatives with appended peptide--sulfonamide and peptide--urea arms. The library was synthesized using the Encore method with SynPhase lanterns as the solid support. A high-throughput assay was developed to screen individual members of the library for an ability to translocate a fluorescent NBD derivative of phosphatidylserine across vesicle membranes. Several lead compounds were identified, and one was synthesized independently to confirm its high phosphatidylserine translocation activity. 相似文献
1000.
Nakanishi S Fukami K Tada T Nakato Y 《Journal of the American Chemical Society》2004,126(31):9556-9557
Strikingly well-ordered Sn latticeworks, standing perpendicular to the substrate, are formed spontaneously in oscillatory electrodeposition. Cooperation of various processes, such as needle formation by autocatalytic crystal growth, cuboid formation under a reaction-limited condition, and autocatalytic oxidation at closest-packed surfaces, enabled the self-organization of the latticeworks. The mechanism is generally applicable to deposition of other metals such as Zn, Pb, and Cu. The present work has opened a promising, unique field toward the formation of highly ordered 3-D micro- or nanostructures at solid surfaces. 相似文献