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1.
Five membered ring carbalkoxy aminimides are prepared from 1,1-dimethylhydrazine and -chloroalkyl chloroformates in three steps. Upon heating, these aminimides give high yields of N,N-dimethylamino isocyanate. This intermediate dimerizes or can be trapped in the presence of a nucleophile. 相似文献
2.
V. V. Charskii A. N. Pavlov G. M. Nazin B. L. Korsunskii B. S. Fedorov 《Russian Chemical Bulletin》1989,38(4):713-716
Conclusions The methylnitroamine radical does not tend to undergo intramolecular oxidation: Me.NNO2 MeO+N2O and breaks down by decomposition into MeN: and NO2. In the presence of NO2 MeNNO2 and MeN: are efficiently oxidized to MeNO.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 794–797, April, 1989. 相似文献
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4.
Upon evaporation at room temperature of an aqueous mixture containing Al(III) sulfate and trishydroxymethyl-ammoniummethane
sulfate in a molar ratio 1:2, double sulfate as crystalline product was obtained. The stoichiometry of the obtained compound
was determined by means of elemental and TG analysis. For identification, IR-spectra and X-ray powder diffraction patterns
were done. It was found that the general formula of the obtained compound is Al(HOCH2)3CNH3(SO4)2·6H2O. as revealed by TG, DTG and DTA analysis, the dehydration of the AL-compound takes place in one step which points out that
the six water molecules are bonded in the same way. The thermal decomposition of the anhydrous compound starts at about 260°C
and is very complex. This process takes place in many steps which are not well resolved. The pathway of the thermal decomposition
is also supposed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
5.
V. V. Dovlatyan K. A. Éliazyan L. G. Agadzhanyan 《Chemistry of Heterocyclic Compounds》1977,13(2):210-213
The reaction of 4,6-bis[alkyl(dialkyl)amino]- or (4-alkylamino-6-dialkylamino-sym-triazin-2-yl)trimethylammonium chlorides with ethylene chlorohydrin and the action of phosphorus pentachloride on 2--hydroxyethoxy-sym-triazines give 2--chloroethoxy derivatives of sym-triazine, which on heating are converted to imidazo[1,2-a]-sym-triazine derivatives.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 262–265, February, 1977. 相似文献
6.
V. V. Dovlatyan A. V. Dovlatyan K. A. Éliazyan R. G. Mirzoyan 《Chemistry of Heterocyclic Compounds》1977,13(10):1140-1143
Reaction of [2-methylthio-6-dialkylamino-sym-triazin-4-yl]trimethylammonium chlorides with ethylene chlorohydrin gave 2-methylthio-4-(2-chloroethoxy)-6-dialkylamino-sym-triazines, which are converted to 2-methylthio-3-(2-chloroethyl)-4-oxo-6-dialkylamino-3,4-dihydro-symtriazines when they are heated to 115–120°C and to the corresponding tetrahydrothiazolo-symtriazine derivatives when they are heated at 180–190°C.See [1] for communication II.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1420–1423, October, 1977. 相似文献
7.
Glover SA White JM Rosser AA Digianantonio KM 《The Journal of organic chemistry》2011,76(23):9757-9763
The first X-ray structures of two anomeric N,N-dialkoxyamides (2 and 3) have been obtained, which confirm that they are highly pyramidalized at nitrogen and have long N-CO bonds, a characteristic of other anomeric amides and a consequence of drastically reduced amidicity. The crystals also demonstrate chirality at the amide nitrogen in the solid state. The structures are well-predicted by density functional calculations using N,N-dimethoxyacetamide as a model. The amidicity of N,N-dimethoxyacetamide has been estimated by two independent methods, COSNAR and a new transamidation method, which give almost identical resonance stabilization energies of -8.6 kcal mol(-1) and only 47% that of N,N-dimethylacetamide computed at the same level. The total destabilization is composed of a resonance and an inductive contribution, which we have evaluated separately. The electronegative oxygens at nitrogen are responsible for localization of the nitrogen lone pair on the amide nitrogen, a factor that contributes to a loss of resonance over and above the impact of pyramidalization at nitrogen, as well as the fact that N,N-dimethoxyacetamide is predicted to protonate on the carbonyl oxygen in preference to nitrogen. 相似文献
8.
Diazetine dioxide 1a has been synthesized in a single step via oxidation of meso-2,3-diphenyl-1,2-ethanediamine with dimethyldioxirane, albeit in low yield (7%). Thermal decomposition of 1a afforded predominantly either trans-stilbene or diphenyl glyoxime depending on solvent, temperature, and the presence of an amine catalyst. Reaction in chloroform at 69 degrees C favored elimination of NO and formation of trans-stilbene. The stereospecific formation of trans-stilbene suggests a mechanism of decomposition in which C-N bond cleavage leads to a diradical intermediate stabilized by the phenyl group. Bond rotation followed by cleavage of the second C-N bond accounts for the trans-stilbene. At 25 degrees C in chloroform, while trans-stilbene was still the major product, some diphenyl glyoxime was also observed (4% yield). However, 1a as a solution in chloroform in the presence of Et3N, or 1a as a solution in DMSO-d6, afforded predominantly diphenyl glyoxime. These results are interpreted in terms of two closely competing reactions subject to the effects of entropic contributions. 相似文献
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10.
N,N-dimethyl-3-oxa-glutaramic acid was purified and characterized by 1H-NMR, Fourier transform infrared spectroscopy (FT-IR) and elemental analysis. The thermal decomposition of the title compound was studied by means of thermogravimetry differential thermogravimetry (TG-DTG) and FT-IR. The kinetic parameters of its second-stage decomposition reaction were calculated and the decomposition mechanism was discussed. The kinetic model function in a differential form, apparent activation energy and pre-exponential constant of the reaction are 3/2 [(1?α)1/3?1]?1, 203.75 kJ·mol?1 and 1017.95s?1, respectively. The values of ΔS ≠, ΔH ≠ and ΔG ≠ of the reaction are 94.28 J·mol?1·K?1, 203.75 kJ·mol?1 and 155.75 kJ·mol?1, respectively. 相似文献
11.
《中国科学B辑(英文版)》2008,(11)
N,N-dimethyl-3-oxa-glutaramic acid was purified and characterized by 1H-NMR, Fourier transform in-frared spectroscopy (FT-IR) and elemental analysis. The thermal decomposition of the title compound was studied by means of thermogravimetry differential thermogravimetry (TG-DTG) and FT-IR. The ki-netic parameters of its second-stage decomposition reaction were calculated and the decomposition mechanism was discussed. The kinetic model function in a differential form, apparent activation energy and pre-exponential constant of the reaction are 3/2 [(1-α) 1/3-1]-1, 203.75 kJ-mol-1 and 1017.95s-1, respec-tively. The values of ΔS≠, ΔH≠ andΔG≠ of the reaction are 94.28 J-mol-1-K-1, 203.75 kJ-mol-1 and 155.75 kJ-mol-1, respectively. 相似文献
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13.
V. V. Semenov N. F. Cherepennikova A. N. Kornev E. V. Naamova N. P. Makarenko S. Ya. Xhorshev G. A. Domrachev O. A. Bochkova 《Russian Chemical Bulletin》1996,45(10):2431-2437
Oligo(phenylcobaltcarbonylsilane) was prepared from oligo(phenylsilane) and dicobalt octacarbonyl. The reaction proceeds with elimination of H2 and CO and insertion of cobalt carbonyl fragments into the silicone backbone of oligosilane. Oligosilane containing cobalt carbonyl groups in side organic substituents was obtained from oligolmethyl(phenylethynyl)Isilane and CO2(CO)8. The reaction of 1,2-bis(phenylethyny1)tetramethyldisilane with Co2(CO)8 proceeds with the sequential attachment of cobalt carbonyl fragments to ethynyl groups to form disilane derivatives [2-CCPhCo2(CO)6] Thermal decomposition of cobalt-containing oligosilanes affords a mixture of paramagnets and ferromagnets.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya. No. 10, pp. 2561–2567, October, 1996. 相似文献
14.
Çi?dem Kad? 《European Polymer Journal》2003,39(2):269-273
Several dimeric peroxycarbamates (PCs) have been synthesized by using cycloaliphatic and aromatic diisocyanates with mono- and di-hydroperoxides. The reactions were carried out under suitable conditions either in the presence of T-12 (dibutyltin dilaurate) as catalyst or in the absence of this catalyst. The products were characterized by IR-spectra and molecular weight measurements from isocyanate and peroxygen analyses. Thermal decomposition kinetics of these PCs were studied in THF solution at 80, 90 and 100 °C; the reactions were found to be first-order and decomposition rate constants (kd) were found. Activation energies and frequency factors for the decomposition were calculated. Activation energies were found to be in the range 67-121 kJ mol−1 and frequency factors were of the order of 1011-1015 s−1 depending on the structure of the PC. The results for the PCs agree well with literature values. 相似文献
15.
O. K. Sharutina V. A. Senchurin V. V. Sharutin G. K. Fukin L. N. Zakharov A. I. Yanovsky Yu. T. Struchkov 《Russian Chemical Bulletin》1996,45(1):186-190
Acyloxy derivatives of tetra phenylantinmony of the general formula Ph4SbOC(O)R (R = Alk or Ar) have been synthesized by the reaction of pemaphenylantimony with carboxylic acids. Thermolysis of the compounds obtained affords phenyl carboxylates and triphenylstibine in quantitative yields. One of these compounds (R = CH=CHPh) has been studied by X-ray structural analysis. In this compound, the Sb atom has a trigonal-bipyramidal coordination. The Sb-O(Ph)eq distances are in the range 2.103(4)-2.140(5) A; the Sb-C(Ph)ax bond length is 2.167(5) A. The fragment of the residue of cinnamic acid has a delocalized double bond in the carboxylate group.Yu. T. Struchkov deceased in 1995.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 194–198, January, 1996. 相似文献
16.
A. Ubaldini C. Artini G. A. Costa M. M. Carnasciali R. Masini 《Journal of Thermal Analysis and Calorimetry》2008,94(3):797-803
Several (Gd1−xNdx)2[C2O4]3·nH2O samples (0≤x≤1) were prepared by a coprecipitation method: the precipitation is quantitative and all the samples are homogeneous in stoichiometry.
XRD analyses have shown that a complete solid solution is formed over the whole range of compositions. The dried Gd rich oxalates
have initially a low water content which gradually increases with the Nd content. All the oxalates decompose in O2 around 700°C either into a single mixed oxide or in a mixture of oxides through several steps, which can be ascribed to the
loss of water and CO2. 相似文献
17.
The preparation of pure K3Al(C2O4)3·mH2O (2<m<3) is described. Dependent on the mode of preparation, the following were found to be contaminants of the desired product: K2C2O4·1H2O; KHC2O4; KHC2O4·H2C2O4·2H2O; H2C2O4·2H2O; different forms of aluminium oxide hydrate; K4Al2(OH)2(C2O4)4· (2+x)H2O (0.7<x<1.7) and K2Al2(H2O)2(C2O4)4· 4H2O. 相似文献
18.
V. V. Nedel'ko A. V. Shastin B. L. Korsunskii N. V. Chukanov T. S. Larikova A. I. Kazakov 《Russian Chemical Bulletin》2005,54(7):1710-1714
Ditetrazol-5-ylamine (DTA) was synthesized from cyanuric chloride in four steps. The thermal decomposition of DTA in the solid
state was studied by thermogravimetry, volumetry, mass spectrometry, IR spectroscopy, and calorimetry. Under isothermal conditions
at 200–242 °C, thermal decomposition obeys the first order autocatalytic kinetics. The kinetic and activation parameters of
DTA decomposition were determined. The composition of gaseous reaction products and the structure of condensed residue were
studied. The thermal effect of thermal DTA decomposition is 281.4 kJ mol−1. The nitrogen content in a mixture of gaseous products formed by the reaction in a temperature interval of 200–242 °C exceeds
97 vol.%.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1660–1664, July, 2005. 相似文献
19.
Yongni Li Xuehang Wu Wenwei Wu Kaituo Wang Liqin Qin Sen Liao Yanxuan Wen 《Journal of Thermal Analysis and Calorimetry》2014,117(1):499-506
CeO2 was synthesized by calcining Ce2(C2O4)3·8H2O above 673 K in air. The precursor and its calcined products were characterized using thermogravimetry and differential scanning calorimetry, Fourier transform infrared spectra, X-ray powder diffraction, scanning electron microscopy, and UV–Vis absorption spectroscopy. The result showed that cubic CeO2 was obtained when the precursor was calcined above 673 K in air for 2 h. The UV–Vis absorption spectroscopy studies showed that superfine CeO2 behaved as an excellent UV-shielding material. The thermal decomposition of the precursor in air experienced two steps, which are: first, the dehydration of eight crystal water molecules, then the decomposition of Ce2(C2O4)3 into cubic CeO2. The values of the activation energies associated with the thermal decomposition of Ce2(C2O4)3·8H2O were determined based on the Starink equation. 相似文献