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Alexander D. Vasiliev Alexander M. Astachov Yuri V. Kekin Ludmila A. Kruglyakova Rudolf S. Stepanov 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(10):1192-1193
The molecule of title compound, C2H7N3O2, has a zwitterionic structure. All non-H atoms, apart from the terminal N atom of the NH3 group, lie in the same plane, with a maximum deviation of 0.056 (1) Å for the amine N atom of the nitramine group, whereas the deviation of the terminal N atom of the NH3 group from the same plane is 1.222 (2) Å. Intermolecular hydrogen bonds within the crystal form a three-dimensional network. 相似文献
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I. A. Pochitalkina P. A. Kekin A. N. Morozov D. F. Kondakov I. A. Petropavlovskii 《Russian Journal of Inorganic Chemistry》2016,61(11):1392-1396
The morphology of calcium carbonate prepared via homogeneous synthesis from carbonate–chloride solutions was studied. The precipitates were investigated by scanning electron microscopy (SEM) and Xray diffraction. The effects of the ratio between the chloride and carbonate components of a solution on the morphology, crystal structure, and particle size of precipitated calcium carbonate were illustrated. 相似文献
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Kruglyakova L. A. Stepanov R. S. Kekin Yu. V. Pekhotin K. V. 《Russian Journal of General Chemistry》2019,89(2):194-198
Russian Journal of General Chemistry - The kinetics of thermal decomposition of 3,7-dinitro-1,3,5,7-tetraazabicyclo[3.3.1]nonane has been studied in solid phase and in solution. The mechanism,... 相似文献
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I. A. Pochitalkina P. A. Kekin A. N. Morozov I. A. Petropavlovskii D. F. Kondakov 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2016,90(12):2346-2351
The formal kinetics of calcium carbonate crystallization in aqueous solutions is studied at a stoichiometric ratio of Ca2+ and CO32- ions. The kinetics of the process was monitored by convenient and reliable methods (complexometric analysis for calcium in an aqueous solution and energy dispersive and microscopic measurement of solid particle sizes). The effect the temperature and degree of supersaturation have on the periods of induction and mass crystallization and the equilibrium concentration of calcium ions in solution is estimated at continuously controlled pH and solution ionic strength. The kinetic parameters (n, k, τ1/2, Ea) of calcium carbonate crystallization are calculated. It is shown that calcium carbonate with a calcite structure formed at a stoichiometric ratio of reagents, and changes in the temperature (25–45°C) and the solution’s degree of supersaturation (2–6) within the considered range had no effect on the characteristics of the solid phase. 相似文献
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A. M. Astakhov A. D. Vasil'ev M. S. Molokeev Yu. V. Kekin L. A. Kruglyakova R. S. Stepanov 《Journal of Structural Chemistry》2003,44(2):326-329
An Xray structural investigation of 2nitro1ureidoguanidine has been carried out. The crystals are monoclinic: a = 4.4690(2), b = 15.566(1), c = 9.4131(7), = 94.896(5)°, V = 652.4(3)>
3, space group P21/n, Z = 4, calc = 1.650 g/cm3. The molecule consists of two planar fragments: carbamide and nitroguanidine. The geometrical characteristics of the molecule are analyzed. The system of intra and intermolecular hydrogen bonds in the crystal is considered. 相似文献
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