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21.
Jain C Morajkar P Schoemaecker C Viskolcz B Fittschen C 《The journal of physical chemistry. A》2011,115(39):10720-10728
Absolute absorption cross sections for selected lines of the OH stretch overtone 2ν(1) of the cis-isomer of nitrous acid HONO have been measured in the range 6623.6-6645.6 cm(-1) using the continuous wave cavity ring-down spectroscopy (cw-CRDS) technique. HONO has been generated by two different, complementary methods: in the first method, HONO has been produced by pulsed photolysis of H(2)O(2)/NO mixture at 248 nm, and in the second method HONO has been produced in a continuous manner by flowing humidified N(2) over 5.2 M HCl and 0.5 M NaNO(2) solutions. Laser photolysis synchronized with the cw-CRDS technique has been used to measure the absorption spectrum of HONO produced in the first method, and a simple cw-CRDS technique has been used in the second method. The first method, very time-consuming, allows for an absolute calibration of the absorption spectrum by comparison with the well-known HO(2) absorption cross section, while the second method is much faster and leads to a better signal-to-noise ratio. The strongest line in this wavelength range has been found at 6642.51 cm(-1) with σ = (5.8 ± 2.2) × 10(-21) cm(2). 相似文献
22.
Crépin D Tugny C Murray JH Aïssa C 《Chemical communications (Cambridge, England)》2011,47(39):10957-10959
Mild intramolecular hydroacylation of α,α-disubstituted 4-alkylidenecyclopropanals has been developed, avoiding decarbonylation and affording cycloheptenones in good yields. The reaction is chemoselective in favour of the alkylidenecyclopropane moiety when potential alkene or alkyne acceptors are tethered to the substrate. 相似文献
23.
Thorp-Greenwood FL Fernández-Moreira V Millet CO Williams CF Cable J Court JB Hayes AJ Lloyd D Coogan MP 《Chemical communications (Cambridge, England)》2011,47(11):3096-3098
A rhenium polypyridine-based molecular vessel is membrane impermeant when empty, but, upon loading with metal ions, the cationic form is taken up by MCF-7 cells, localising in nucleoli. The luminescence of the vessel and its copper binding ability suggest potential as a bimodal fluorescence/PET imaging agent. 相似文献
24.
Wen Chao Jim Jr‐MinLin Kaito Takahashi Alexandre Tomas Lu Yu Yoshizumi Kajii Sbastien Batut Coralie Schoemaecker Christa Fittschen 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(15):5067-5071
Recent reports [Jara‐Toro et al., Angew. Chem. Int. Ed. 2017 , 56, 2166 and PCCP 2018 , 20, 27885] suggest that the rate coefficient of OH reactions with alcohols would increase by up to two times in going from dry to high humidity. This finding would have an impact on the budget of alcohols in the atmosphere and it may explain differences in measured and modeled methanol concentrations. The results were based on a relative technique carried out in a small Teflon bag, which might suffer from wall reactions. The effect was reinvestigated using a direct fluorescence probe of OH radicals, and no catalytic effect of H2O could be found. Experiments in a Teflon bag were also carried out, but the results of Jara‐Toro et al. were not reproducible. Further theoretical calculations show that the water‐mediated reactions have negligible rates compared to the bare reaction and that even though water molecules can lower the barriers of reactions, they cannot make up for the entropy cost. 相似文献
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Audoin Coralie Holderith Serge Romari Khadidja Thomas Olivier P. Genta-Jouve Grégory 《平面色谱法杂志一现代薄层色谱法》2014,27(5):328-332
JPC – Journal of Planar Chromatography – Modern TLC - Although the different practical steps of a high-performance thin-layer chromatography (HPTLC) experiment are now all automated,... 相似文献
28.
Alonso C Bringezu F Brezesinski G Waring AJ Zasadzinski JA 《Langmuir : the ACS journal of surfaces and colloids》2005,21(3):1028-1035
Monolayer properties such as phase behavior, collapse pressure, and surface viscosity are determined by monolayer composition. Learning how to control these properties through simple additives is important to understanding lung surfactant monolayers and to designing optimal replacement surfactants for treatment of disease. The properties of Infasurf, a replacement lung surfactant derived from calf lung lavage organic extract, can be modified in a controlled fashion by adding hexadecanol (HD). Grazing incidence X-ray diffraction shows that the HD preferentially interacts with dipalmitoylphosphatidylcholine (DPPC), the main phospholipid component of Infasurf, in the same way as in binary mixtures of DPPC and HD. HD intercalates between the DPPC chains, which leads to a tighter packing of the two-dimensional lattice and greater stability of the solid phase. This molecular reorganization triggers changes at the macroscopic scale, leading to a greatly increased solid-phase fraction at a given surface pressure and order of magnitude increases in the surface shear viscosity. However, the collapse pressure decreases, and, hence, the minimum surface tension of the film increases. 相似文献
29.
S. Duchemin M. C. Artaud F. Ouchen J. Bougnot A. M. Pougnet 《Journal of Structural Chemistry》1994,35(3):399-403
30.
Coralie Nyffenegger 《Tetrahedron letters》2007,48(29):5069-5072
A Sonogashira/copper(I)-catalyzed heteroannulation sequence was developed to convert 3,5-diamino-6-chloro-1,2,4-triazines to the corresponding 3-amino-5H-pyrrolo[2,3-e]-1,2,4-triazine derivatives in good yields. 相似文献