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51.
52.
The efficiency of oxygen transfer from the transannular ozonide 1 to several organic substrates was investigated. The efficiency was estimated to be as high as 90% in the case of Ph3P as the substrate. 相似文献
53.
(Perfluoroalkyl)phenyliodonium sulfonates underwent novel oxy-perfluoroalkylation with alkenes under oxygen atmosphere in the presence of a base. 相似文献
54.
The Ag induced superstructures on the Si(111) surface have been studied by low energy electron diffraction constant momentum transfer averaging (LEED/CMTA) technique. The vertical displacements of the atoms are determined from the analysis of the specularly reflected (00) beam intensities. Unexpected behavior of the Ag atoms is clarified: For the √3 × √3-Ag surface it is verified that the Ag atoms are embedded in the first double layer of Si, leading to a considerable rearrangement of the substrate. In contrast, for the 3 × 1-Ag surface, the Ag atoms are riding on the Si surface and the reconstruction of the substrate is small. 相似文献
55.
The system Au/Si(100) has been studied using LEED and AES. Au films grow as Au(111) | Si(100) having six azimuthally rotated orientations at low deposition temperatures below 50°C after the formation of intermediate gold suicide layers. Crystalline gold silicide thin layers are formed on the Au(111) film after heat treatment at 100–400°C. Two types of suicide LEED pattern observed seem to have no correlation with crystallographic data reported on quenched alloy films. Heat treatment over 450°C leads to agglomeration of the film, producing a series of Au-induced superstructures. Heat treatment of the Au film over 1000°C regenerates the clean Si surface accompanied with many etch pits. 相似文献
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Energy distributions of He+ ions scattered by Au and Ag surfaces are measured by an ISS system with high energy resolution, at a scattering angle of 90° and at incident ion energies ranging from 277 to 977 eV. It is found that the observed peak energies deviate toward the low energy side by several electron-volts with respect to the calculated elastic single collision energies. Both the deviation Q' and the inelastic loss energy Q are plotted as a function of incident ion energy for the Au surface. 相似文献
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59.
1,3-Di-tert-butylisobenzofuran reacts with singlet oxygen with rate constant of 2.8 x 109 M?1 sec?1 to give stable endoperoxide . Thermolysis of the endopepoxide () in the ppesence of norbornene and naphthalene gave the corrpesponding epoxide and naphthols, respectively. Addition of Pd(OAc)2 improved the yield of naphtols considepably. 相似文献
60.
Ji-Ben Meng Da-Ming Du Guo-Xiang Xiong Wen-Guang Wang Yong-Mei Wang Hideko Koshima Teruo Matsuura 《Journal of heterocyclic chemistry》1994,31(1):121-124
The solid-state photoreaction of the mixed crystals between nitrobenzaldehydes and indole was found to give nitrophenyl-(bis-3-indolyl)methane ( 3 ) and nitrophenyl-(3-indolyl)methanol ( 4 ). The structure of the ortho isomer 4c was established by X-ray crystallographic analysis. A dual pathway from an oxetane intermediate 5 is proposed for the formation of 3 and 4 . 相似文献