- Gas-Phase Reaction of 1,1-Dimethylhydrazine with Nitrogen Dioxide
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The gas-phase reaction of part-per-million concentrations of nitrogen dioxide with 1,1-dimethylhydrazine in air and in N2 at 298 K was investigated by in situ long-path Fourier transform infrared (FT IP) spectroscopy.In both air and N2, the reaction occurs with an apparent overall rate constant (defined in terms of rates of hydrazine decay) of (2.3 +/- 0.2) * 10-17 cm3 molecule-1 s-1.The major products were nitrous acid and tetramethyltetrazene-2, with the overall reaction stoichiometry being (CH3)2NNH2 + 2NO2 -> 2HONO + 1/2 (CH3)2NN=NN(CH3)2, regardless of initial reactant concentration ratios or whether the reaction was carried out in air or in N2.There was no observable reaction of NO with (CH3)2NNH2 in N2.However, when NO2 was also present, NO participates in the reaction, causing formation of N2O, N-nitrosodimethylamine, and significant amounts of an unidentified compound believed to be an N-nitrosohydrazine, in addition to HONO and tetramethyltetrazene-2.Probable mechanisms accounting for these observations are discussed.
- Tuazon, Ernesto C.,Carter, William P. L.,Brown, Richard V.,Winer, Arthur M.,Pitts, James N.
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- Chromogenic Reaction of 1,1-Dimethylhydrazine with Aryltetrazolium Salts
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The reactions of 1,1-dimethylhydrazine with 2,3,5-triphenyl-2Н-tetrazolium and 2,5-diphenyl-3-(4-nitrophenyl)-2Н-tetrazolium chlorides in a solution and on a cellulose carrier have been studied by means of spectrophotometry and chromato–mass spectrometry to develop new chromogenic indicators for detection of 1,1-dimethylhydrazine. 1,3,5-Triphenylformazan and 1,3-diphenyl-5-(4-nitrophenyl)formazan are formed in these reactions, respectively; deep red shifts have been observed. Other products of these reactions result from oligomerization and addition of short-living 1,1-dimethylhydrazyl and tetrazolium radicals.
- Ostrovskaya,Shchepilov,Kletter
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p. 1385 - 1389
(2018/09/11)
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- Catalyst for the degradation of 1,1-dimethylhydrazine and its by-product N-nitrosodimethylamine in propellant wastewater
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A three-component metal catalyst was prepared and used in the process of catalytic wet peroxide oxidation (CWPO) for the degradation of unsymmetrical dimethylhydrazine (UDMH) in propellant wastewater with H2O2. It was structurally characterized using scanning electron spectroscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray spectroscopy (EDX), and its catalytic activity was evaluated using indexes such as the efficiency of UDMH degradation and chemical oxygen demand (COD) removal and the concentrations of ammonia (NH3-N), formaldehyde (HCHO), total nitrogen (TN), total organic carbon (TOC) and N-nitrosodimethylamine (NDMA). Besides, the reaction system was monitored using UV-Vis full wavelength scanning spectroscopy and liquid chromatography-mass spectroscopy (LC-MS). As a result, it was observed that the degradation mechanism involved OH attacking the amino group and homocoupling in UDMH with the simultaneous transformation of the active component CuII/I. Based on investigation of the reaction factors (H2O2 dosage, temperature, catalyst dosage, pH and initial concentration of UDMH) focusing on the removal of NDMA, the optimal conditions for CWPO with a three-component metal catalyst were determined. The high treatable concentration of UDMH (500 mg L-1), rapid rate and good reusability with a high efficiency of UDMH degradation and COD removal (99.9% in 10 min and 94.6% in 30 min, respectively) and the low concentration of NDMA are merits of the present catalyst.
- Liang, Meiling,Li, Weijie,Qi, Qi,Zeng, Pingchuan,Zhou, Yucheng,Zheng, Yingping,Wu, Min,Ni, Henmei
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p. 5677 - 5687
(2016/02/05)
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- Liquid missile propellants in the former Soviet Union
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The liquid missile propellant unsymmetrical dimethylhydrazine (UDMH) is a very toxic and persistent organic chemical that was widely used in the missile industry of the former Soviet Union. Only in the last few years have Russian authorities acknowledged the dangers of this fuel to people and nature. To date, little has been done for the transition towards fuels with a lower toxicity. This paper describes the chemical nature of UDMH, and considers its potential impacts on nature and human health. Copyright (C) 1999 ElsevierScience Ltd. All rights reserved.
- Fedorov
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p. 157 - 161
(2007/10/03)
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- REACTIONS OF 1,1-DIALKYLDIAZENIUM SALTS WITH KETONE ETHYLHYDRAZONES
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By reaction of dialkyldiazenium salts with ketone ethylhydrazones, we prepared and characterized 3,3-disubstituted 3,4-dihydroformazans for the first time.The composition of the reaction mixtures indicates a lower (as compared with aldehyde hydrazones) reactivity of ketone hydrazones.
- Kuznetsov, M. A.,Kuznetsova, L. M.,Zasukhina, E. A.
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p. 1363 - 1366
(2007/10/02)
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- The Liquid-phase Oxidation of 1,1-Dimethylhydrazine by Ozone
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The oxidation of liquid 1,1-dimethylhydrazine by oxygen and ozone-oxygen mixtures has been investigated.It has been shown by chromatographic and mass-spectrometric analyses that different products of the incomplete oxidation of 1,2-dimethylhydrazine are formed in both cases: dimethylamine, nitrosodimethylamine, dimethylformamide, tetramethyltetrazene, etc.An increase of the rate of the process and of the contribution by far-reaching oxidation processes, leading to the formation of carbon dioxide, nitrogen, and water, is observed in the oxidation by the ozone-oxygen mixture.
- Gorlenko, L.E.,Emel'yanova, G.I.,Strel'nikova, Zh.V.,Strakhov, B.V.
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p. 1772 - 1774
(2007/10/02)
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- Reaction of 1,1-Disubstituted Hydrazines with Diethyl Azodicarboxylate
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The reaction of hydrazine derivatives 1 with diethyl azodicarboxylate (2) gives primarily the aminonitrenes 3, which add to the azodicarboxylate 2 forming the instable aminoazimines 7.These decompose by rearrangement to urethanes 8 and azidoformic acid ester 9.Furthermore the tetrazenes 5 are formed.The amount of 5 depends on the reaction conditions.
- Fahr, Egon,Koch, Karl-Heinz
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p. 219 - 222
(2007/10/02)
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