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41.
The vertical ionization potentials of difluoramine are calculated by perturbation corrections to Koopmans' theorem. The calculation shows that difluoraimine has three overlapping bands between 15 and 16 eV. The calculated results compare well with the experimental values. The photoelectron spectrum of difluoramine is compared with that of OF2 and CH2F2. 相似文献
42.
Low-lying vacant molecular orbitals may lead not only to a breakdown of Koopmans' theorem but also to satellite structure in photoelectron spectra. This paper reports examples of the relatively infrequent appearance of shake-up satellites in Hel photoelectron spectra, namely those of N2O4 and CH3NO. An extended version of the HAM/3 program was used to interpret these spectra. 相似文献
43.
Qing Jie Zhao Yan Song Hong Gang Hu Shi Chong Yu Qiu Ye Wu School of Pharmary Second Military Medical University Shanghai China 《中国化学快报》2007,18(6):670-672
Twenty-three 1 -(1H-1,2,4-triazole-1 -y1)-2-(2,4-difluorophenyl)-3-(iV-cycloproyl-N-substituted-amino)-2-propanols were designed and synthesized on the basis of the active site of lanosterol 14α-demethylase. In vitro antifungal activities showed that some of the title compounds had higher antifungal activity and broader antifungal spectrum than fluconazole. 相似文献
44.
45.
[reaction: see text] Copper(I)-mediated C-N bond formation has been employed to prepare both N-acyl vinylogous carbamic acids and ureas. The novel N-acyl vinylogous carbamic acid antibiotic, CJ-15,801, was synthesized using this methodology. 相似文献
46.
Thiam Seong Chong 《Journal of organometallic chemistry》2006,691(4):687-692
The rate constant for the methyl abstraction reaction of CpFe(CO)2Me has been measured with the benzyl radical clock as (1.1 ± 0.2) × 105 M−1 s−1 at room temperature. Time-resolved Fourier-transform Infrared (FTIR) absorption spectroscopy pointed towards the formation of the CpFe(CO)2 radical upon benzyl abstraction. The main stable product has been established by a linear scan of the reaction mixture as Cp2Fe2(CO)4 produced by the dimerization of the CpFe(CO)2 radicals. The transition state structure for the abstraction process was also found at UB3LYP/6-311+G* level of theory to contain a planar CH3 group. 相似文献
47.
A study of the reaction of Me3SnCu·.Me2S (1) and [Me3SnCuSPh]Li (2) with α,β - acetylenic N,N-dimethylamides 3 shows (a) that the overall process can be controlled experimentally so as to produce either N,N-dimethyl ()-(4) or ()-3-trimethylstannyl-2-alkenamides (5), (b) that the initially formed intermediate derived from interaction of 2 and 3 is significantly more stable than that obtained by reaction of 2 and α,β-acetylenic esters, and (c) that the intermediate produced by treating 3 with 1 can be trapped with electrophiles other than proton. 相似文献
48.
Chong‐Hyeak Kim Sueg‐Geun Lee 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(7):m421-m423
The title compound, [Ni(C3H10N2)2(H2O)2](C6H6NO3S)2, contains alternating layers of sulfanilate anions and diaquabis(1,3‐propanediamine)nickel(II) cations. The Ni atom lies on an inversion centre and is hexacoordinated by the 1,3‐propanediamine ligands, which function as N,N′‐bidentate ligands, and the water molecules, which are in a trans arrangement. The sulfanilate anions are arranged in layers, with the sulfonate and amine groups directed towards opposite sides of the layer. The structure is stabilized by a network of hydrogen bonding between the O and N atoms of the sulfanilate anions, the water molecules, and the N atoms of the 1,3‐propanediamine ligands. 相似文献
49.
Adsorption of NH3 onto activated carbon prepared from palm shells impregnated with H2SO4 总被引:3,自引:0,他引:3
Adsorption of ammonia (NH3) onto activated carbons prepared from palm shells impregnated with sulfuric acid (H2SO4) was investigated. The effects of activation temperature and acid concentration on pore surface area development were studied. The relatively large micropore surface areas of the palm-shell activated carbons prepared by H2SO4 activation suggest their potential applications in gas adsorption. Adsorption experiments at a fixed temperature showed that the amounts of NH3 adsorbed onto the chemically activated carbons, unlike those prepared by CO2 thermal activation, were not solely dependent on the specific pore surface areas of the adsorbents. Further adsorption tests for a wide range of temperatures suggested combined physisorption and chemisorption of NH3. Desorption tests at the same temperature as adsorption and at an elevated temperature were carried out to confirm the occurrence of chemisorption due to the interaction between NH3 and some oxygen functional groups via hydrogen bonding. The surface functional groups on the adsorbent surface were detected by Fourier transform infrared spectroscopy. The amounts of NH3 adsorbed by chemisorption were correlated with the contents of elemental oxygen present in the adsorbents. Mechanisms for chemical activation and adsorption processes are proposed based on the observed phenomena. 相似文献
50.
Chong BE Lubman DM Rosenspire A Miller F 《Rapid communications in mass spectrometry : RCM》1998,12(24):1986-1993
Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) has been used to rapidly profile the protein content of human cell lysates from MCF-10 cell and variant lines. The method was used to study the protein profiles of these cells as they progressed from normal breast epithelium to fully malignant cells. Distinct differences in the protein profiles were observed with progression, and specific proteins associated with carcinogenesis (p53, c-myc, and c-erbB-2) were heavily expressed in these cells as detected by MALDI-TOFMS. These proteins were also isolated using non-porous reversed-phase high performance liquid chromatography (NP-RP-HPLC) and mass analyzed by MALDI-TOFMS to provide molecular weight information without interference from other proteins in the whole cell lysates, and to avoid suppression effects in mixtures of proteins detected by MALDI-TOFMS. In order to confirm the identity of these oncoproteins, the cell lysates were subjected to one-dimensional (1-D) gel separation and subsequently electroblotted onto a poly(vinylidene difluoride) (PVDF) membrane for further analysis. Trypsin and cyanogen bromide digestions were performed on these proteins eluted from excised PVDF bands which were then analyzed by MALDI-TOFMS. The identity of these proteins was confirmed by database matching procedures. 相似文献