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1.
[reaction: see text] Anomalous ozonolysis of strained bicyclic allylic alcohols yields alpha-hydroxymethyl ketones. The proposed mechanism involves an unusual trapping of the primary ozonide that undergoes a Grob-like fragmentation instead of dissociating into the Criegee intermediates. 相似文献
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J. Tichy M. M. Andrushkevich G. K. Boreskov A. A. Davidov L. M. Plyasova V. D. Sokolovskii 《Reaction Kinetics and Catalysis Letters》1976,5(4):407-413
The products of selective oxidation are shown to be formed via a stepwise mechanism with participation of surface allylic complexes. A successive transformation of -allyl to -allyl and further to acrolein is possible. The products of complete oxidation may be formed through surface carbonate-carboxylate complexes via either a stepwise mechanism involving the catalyst's oxygen, or a concerted mechanism with the participation of molecular oxygen.
, . - -, . - , .相似文献
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C. Rettori D. Davidov J. Suassuna G.E. Barberis B. Elschner D. Born 《Solid State Communications》1978,25(8):543-546
ESR studies of the rare earth ions Gd, Dy, and Er in Cerium metal are reported for the first time. Evidence that the ESR measurements were performed in the α-Cerium phase is provided. Comparison of our results with previous α-La:Gd and Th:Gd ESR studies supports the idea that the f band contribution to the ESR linewidth and g shift in α-Ce can be neglected. This assumption enable us to extract the enhancement factors of the host d-s and f conduction bands of α-Ce as well as the impurity-conduction electron exchange parameters for Gd, Dy and Er in α-Ce. 相似文献
7.
X-ray diffraction study of the CDW phase in (TaSe4)2I: Determination of the CDW modulation amplitude
An extensive X-ray diffraction study of charge density wave (CDW) phase in (TaSe4)2I is reported. We have observed the superstructure satellites at 2q in addition to those at q reported by Fujishita et al. The results imply a sinusoidal lattice modulation with polarization almost perpendicular to q (i.e. transverse) and the existence of CDW domains. At 15 K we have extracted an approximate value for the amplitude of the lattice modulation perpendicular to q to be μ⊥ ∽ 0.087 Å. 相似文献
8.
V. B. Akopyan M. V. Bambura E. R. Davidov A. Yu. Stupin O. I. Chubatova 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2010,84(3):425-428
Substances concentrated by surface sorption at a liquid-gas interface can be isolated by transforming the surface layer of the liquid using high-frequency focused ultrasound into an aerosol followed by aerosol condensation. The concentration of the surface substance in the obtained condensate is several times higher than in the initial solution. The effect was most pronounced at low contents of surface active component in the initial solution. 相似文献
9.
Detlef Gabel Claudia Bauer Mohamed E. El-Zaria Afaf R. Genady Udo Drfler 《Journal of organometallic chemistry》2003,680(1-2):23-26
The preparation and properties of the R1R2NH---B8H11NHR cluster are described. The cluster is stable to aqueous solutions and can be made water-soluble by the introduction of a few hydrophilic groups. This makes the cluster a good candidate as the boron moiety in compounds for boron neutron capture therapy. The chemistry of the cluster preparation, the stability of the cluster, and conditions for reactions of the organic moieties are reviewed. Pyridine derivatives of the cluster show electronic interaction between the cluster and the pyridine. 相似文献
10.
Nasser R. El-Brollosy Mohamed F. Abdel-Megeed Afaf R. Genady 《Monatshefte für Chemie / Chemical Monthly》2001,14(1):1063-1073
A facile and efficient synthesis of a series of novel 1,2,4-triazolo[5,1-b]quinazolines is described. 2,3-Diaryl-2,3-dihydro-1H-1,2,4-triazolo[5,1-b]quinazolin-9-ones were obtained by reaction of 3-amino-2-arylamino-3H-quinazolin-4-ones with aromatic aldehydes as well as by ring closure of the corresponding anils. Treatment of 3-amino-2-arylamino-3H-quinazolin-4-ones with aromatic carboxylic acids afforded 2,3-diaryl-3H-1,2,4-triazolo[5,1-b]quinazolin-9-ones which could also be synthesized by dehydrogenation of the corresponding dihydro derivatives. Reaction of 3-amino-2-arylamino-3H-quinazolin-4-ones with diethyl malonate and acetylacetone gave 3-aryl-3,9-dihydro-9-oxo-1,2,4-triazolo[5,1-b]quinazolin-2-yl-acetic acid ethyl ester and 3-aryl-2-methyl-3H-1,2,4-triazolo[5,1-b]quinazolin-9-ones, respectively. The latter compounds were also prepared via reaction with acetic anhydride, whereas acetylation with acetic anhydride in the presence of pyridine afforded the acetyl derivatives. 相似文献