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The compounds previously reported2 to be the stable areneselenenic acids, -nitro-( and -benzoylbenzeneselenenic acid (), are shown actually to be the corresponding selenenic anhydrides (ArSeOSeAr). Solutions of the selenenic acids (ArSeOH), however, can be easily generated from the anhydrides byacid-catalyzed hydrolysis. 相似文献
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Summary The 1,3-dipolar cycloaddition reactions of 4,6-diazaphenanthrene 6-phenacylide formed in situ from the appropriate quaternary bromide in basic medium were investigated; as dipolarophiles acrylonitrile, ethyl acrylate,n-butyl acrylate and diethyl maleate were used.
1,3-Dipolare Cycloadditionsreaktionen von 4,6-Diazaphenanthren-6-phenacylid
Zusammenfassung Es wurden die 1,3-dipolaren Cycloadditionen von 4,6-Diazaphenanthren-6-phenacylid untersucht, welches in situ aus dem entsprechenden quaternären Bromid in Gegenwart von Alkali dargestellt wurde. Als Dipolarophile wurden Acrylnitril, Ethylacrylat,n-Buthylacrylat und Diethylmaleat eingesetzt.相似文献
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The title compounds 4 have been obtained in high yields in a one-step sequence by the Mitsunobu reaction of diethyl 1-hydroxyalkylphosphonates 1 with hydrazoic acid, and subsequence treatment of the inter-mediate azides 2 with triphenylphosphine, followed by hydrolysis of the iminophosphoranes 3 with water. 相似文献
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Książczak A. Boniuk Henryka Cudziło S. 《Journal of Thermal Analysis and Calorimetry》2003,74(2):569-574
Simultaneous TG/DTA has been used to study the thermal decomposition of binary compositions containing polytetrafluoroethene
(PTFE) with silicon (Si), calcium silicide (CaSi2), ferrosilicon (FeSi) or iron (Fe) powders. In nitrogen and under dynamic heating program the thermal decomposition of Si/PTFE
and CaSi2/PTFE is an exothermic process. The other two compositions decompose endothermically. In each case the decomposition reactions
show first-order kinetics but only iron does not change considerably the kinetics of PTFE depolymerization. The constants
of the decomposition rate at 850 K for silicon containing reducers are about four times higher than those of PTFE and Fe/PTFE.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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The mass spectra of seventeen different quinoxaline halogeno derivatives are reported. The fragmentation mechanism is discussed. 相似文献
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Henryka Siejka 《Israel Journal of Mathematics》1986,54(3):291-300
The class Σb is defined to consist of meromorphic univalent functionsH omitting a disc with the radiusb:H(z)=z+ Σ
0
∞
A
n
z
−n
,z>1,H(b)>b ∈ (0, 1). By aid of FitzGerald inequalities the inverse coefficients of odd Σb-functions are maximized. The result extends the corresponding estimation, due to Netanyahu and Schober, fromb=0 to the whole interval (0, 1).
The author wishes to express her gratitude to Professor O. Tammi for valuable discussions connected with the problem.
This work was supported by a grant from the Finnish Ministry of Education. 相似文献
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