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101.
Pyridine accelerates the decomposition of triphenylphosphite ozonide in CH2Cl2. The addition of ethanol to the (PhO)3PO3-C5H5N-CH2Cl2 system increases the rate of the process. The kinetic regularities of the decomposition of (PhO)3PO3 in the presence of pyridine, ethanol-pyridine, and propan-2-ol-pyridine mixtures in CH2Cl2 are studied.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 871–873, May, 1995.This work was financially supported by the Russian Foundation for Basic Research (Project No. 93-03-5231). 相似文献
102.
Temperature-programmed retention indices for eleven cyclic organic peroxides were determined by gas chromatography on slightly
polar 5% biphenyl 95% dimethylpolysiloxane columns (DB-5 and Rtx-5MS) at three heating rates (5, 10, and 20° min−1) from 60 to 300°C, using different chromatographs. Cyclic organic diperoxides and triperoxides had nearly constant retention
indices when different heating rates and a short isothermal hold time (5 min) before the programmed increase in temperature
were used. The usefulness of temperature-programmed retention indices was shown by using the data to predict the retention
times and structures of unknown diperoxides or triperoxides derived from ketones. This is the first step in the identification
of unknown cyclic organic peroxides, a process would otherwise require the availability of reference compounds.
Revised: 7 and 17 November 2005 相似文献
103.
The novel peroxides H2NSO2OOCH2
R (1 a:R=CH2CH3;1 b:R=CH2CH2CH3) are obtained by reaction of sulphamoyl chloride with the appropriate hydroperoxides in the presence of pyridine (temperature below –30 °C, solvent diethyl ether). The solvent-free liquids1 deflagrate at ca. 0 °C. Hydrolysis or ammonolysis of1 generates the hydroperoxide and sulphamic acid or sulphamide, respectively. Controlled thermolysis of1 affords sulphamic acid and carbonyl compounds, i.e. propanal andn-propyl propanoate from1 a, butanal, 2-methylpropanal andn-butyln-butyrate from1 b. These products suggest a nonradical cyclic decomposition path-way. 相似文献
104.
A. O. Terent"ev A. V. Kutkin M. M. Platonov I. I. Vorontsov M. Yu. Antipin Yu. N. Ogibin G. I. Nikishin 《Russian Chemical Bulletin》2004,53(3):681-687
Aliphatic and alicyclic gem-bis-hydroperoxides and their derivatives, bis(1-hydroperoxycycloalkyl) and bis(1-hydroperoxyalkyl) peroxides, dispiro- and tetraalkyl-1,2,4,5-tetroxanes were synthesized by the reaction of aliphatic and alicyclic acetals and enol ethers with H2O2 in the presence of BF3 in anhydrous Et2O. 相似文献
105.
Reaction mechanisms for the isomerization of prostaglandin H2 to thromboxane A2, and degradation to 12‐L‐hydroxy‐5,8,10‐heptadecatrienoic acid (HHT) and malondialdehyde (MDA), catalyzed by thromboxane synthase, were investigated using the unrestricted Becke‐three‐parameter plus Lee–Yang–Parr (UB3LYP) density functional level theory. In addition to the reaction pathway through FeIV‐porphyrin intermediates, a new reaction pathway through FeIII‐porphyrin π‐cation radical intermediates was found. Both reactions proceed with the homolytic cleavage of endoperoxide O? O to give an alkoxy radical. This intermediate converts into an allyl radical intermediate by a C? C homolytic cleavage, followed by the formation of thromboxane A2 having a 6‐membered ring through a one electron transfer, or the degradation into HHT and MDA. The proposed mechanism shows that an iron(III)‐containing system having electron acceptor ability is essential for the 6‐membered ring formation leading to thromboxane A2. Our results suggest that the step of the endoperoxide O? O homolytic bond cleavage has the highest activation energy following the binding of prostaglandin H2 to thromboxane synthase. 相似文献
106.
107.
Bin Qi Zhongming Chen Kesheng Shao Min Hu Yuanhang Zhang Xiaoyan Tang 《中国科学B辑(英文版)》1998,41(5):488-493
The formation of organic peroxides in the Cl-atom-initiated photooxidation of CH4 in O2-N2 mixtures at 101 325 Pa and 298 K was studied with HPLC and FT-IR methods. Four peroxidic products were detected, which were
H2O2, hydroxymethyl hydroperoxide (HOCH2OOH; HMHP), methyl peroxide (CH300H; MHP) and dimethyl peroxide (CH300CH3). A chromatogram peak at retention time of 8.08 min was assigned tentatively to peroxyformic acid (HC(O)OOH). The identification
of HMHP in the reaction system showed that one of the reaction paths for the self-reaction of CH300. led to producing Criegee intermediate CH2OO. The formation mechanism of organic peroxide in the photooxidation of CH4 is more complicated than it was assumed before. Photooxidation of CH4 is probably an important source of organic peroxides in the troposphere.
Project supported by the State Scientific and Technological Commission of China (Grant No. E96-05) 相似文献
108.
Back Cover: Peroxide Coordination of Tellurium in Aqueous Solutions (Chem. Eur. J. 9/2016) 下载免费PDF全文
109.
利用高效液相色谱测定了北京和广州地区大气过氧化物浓度,并分析了相关因素对过氧化物浓度变化的影响。北京地区在5月、6月和9月3个监测时段中H2O2的平均浓度分别为2.33×10-9、0.338×10-9和0.148×10-9;广州11月H2O2的平均浓度为0.168×10-9(VH2O2/Vair)。植物排放对有机过氧化物的生成有一定贡献,有机过氧化物浓度变化与H2O2浓度变化具有较好的一致性。过氧化物浓度与O3和甲醛浓度表现出较好的正相关性,而与SO2浓度则表现出负相关性。 相似文献
110.
HPLC along with FT-IR technique was used to study the formation of organic peroxides in the Cl2-ethane-air photoreaction system. Ethyl hydroperoxide (CH3CH21OOH, EHP) and peroxyacetic acid ( CH3C(O)OOH, PAA) were conformed to be the peroxide product in the reaction system. In addition, methyl hydroperoxide (CH3OOH, hydroxymethyl hydroperoxide (HOCH2OOH, HMHP) and two unidentified organic peroxides were detected for the first time. EHP and were the dominant peroxide products.
The identification of HMHP showed that Criegee biradical CH2OO may be formed as an intermediate in the oxidation of ethane. Simulation results showed that photooxidation of ethane may
make substantial contribution to source of organic peroxides in the atmosphere. 相似文献