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1.
A. Yu. Manakov L. S. Aladko A. G. Ogienko A. I. Ancharov 《Journal of Thermal Analysis and Calorimetry》2013,111(1):885-890
The phase diagram of the binary system n-propanol alcohol–water was investigated with use of differential thermal analysis and powder X-ray diffraction. The phase diagram has three groups of thermal effects, which can be considered as peritectic melting of three different hydrates (?60.0, ?53.5, and ?41.5 °C). At the same time, powder X-ray diffraction data indicate the existence of only one compound in this system (cubic unit cell, a = 12.09 ± 0.01 Å and 12.15 ± 0.01 Å at ?109 to ?66 °C, respectively). The most probable explanation of this contradiction seems to be the existence of several hydrates belonging to the same structural type but different in composition. 相似文献
2.
Ogienko AG Kurnosov AV Manakov AY Larionov EG Ancharov AI Sheromov MA Nesterov AN 《The journal of physical chemistry. B》2006,110(6):2840-2846
For the first time, the compositions of argon and methane high-pressure gas hydrates have been directly determined. The studied samples of the gas hydrates were prepared under high-pressure conditions and quenched at 77 K. The composition of the argon hydrate (structure H, stable at 460-770 MPa) was found to be Ar.(3.27 +/- 0.17)H(2)O. This result shows a good agreement with the refinement of the argon hydrate structure using neutron powder diffraction data and helps to rationalize the evolution of hydrate structures in the Ar-H(2)O system at high pressures. The quenched argon hydrate was found to dissociate in two steps. The first step (170-190 K) corresponds to a partial dissociation of the hydrate and the self-preservation of a residual part of the hydrate with an ice cover. Presumably, significant amounts of ice Ic form at this stage. The second step (210-230 K) corresponds to the dissociation of the residual part of the hydrate. The composition of the methane hydrate (cubic structure I, stable up to 620 MPa) was found to be CH(4).5.76H(2)O. Temperature dependence of the unit cell parameters for both hydrates has been also studied. Calculated from these results, the thermal expansivities for the structure H argon hydrate are alpha(a) = 76.6 K(-1) and alpha(c) = 77.4 K(-1) (in the 100-250 K temperature range) and for the cubic structure I methane hydrate are alpha(a) = 32.2 K(-1), alpha(a) = 53.0 K(-1), and alpha(a) = 73.5 K(-1) at 100, 150, and 200 K, respectively. 相似文献
3.
Andrey Yu. Manakov Andrey G. Ogienko Vladislav Yu. Komarov Aleksei I. Ancharov Michail A. Sheromov 《Journal of inclusion phenomena and macrocyclic chemistry》2007,58(3-4):317-320
X-ray diffraction study of quenched sample of acetone clathrate hydrate synthesized at 0.8 GPa was carried out. It was shown
that the host frameworks of the hydrate comprise uniform cavities which are similar to that of recently characterized structure
of high-pressure tetrahydrofurane hydrate. The unique peculiarity of investigated hydrate is decrease in the crystallographic
symmetry of the hydrate arising from ordering in guest subsystem. 相似文献
4.
T. S. Sukhikh D. S. Ogienko D. A. Bashirov N. V. Kuratieva V. YU. Komarov M. I. Rakhmanova 《Journal of Coordination Chemistry》2016,69(21):3284-3293
New polymeric cadmium complexes, α-[CdLCl2]n (1), [CdL2Cl2]n (2) and β-[CdLCl2]n (3) (L = 4-amino-2,1,3-benzothiadiazole), were obtained as products of the reaction of CdCl2 with L. The synthetic procedures allowing isolation of pure 1–3 were optimized. The structures of 1–3 were established by single-crystal X-ray diffraction and the compounds were characterized by UV–Vis and IR spectroscopy. In these compounds, L is either μ-bridging (1) or terminal (2 and 3). The UV–Vis spectra of the complexes in the solid state resemble that of free L. However, coordination of L leads to a significant shift of emission in photoluminescence spectra from yellow (free L) to red (1–3). 相似文献
5.
Andrew G. Ogienko Elissa A. Ukraintseva Tatyana A. Chingina Vladislav Yu. Komarov Andrey Yu. Manakov 《Journal of inclusion phenomena and macrocyclic chemistry》2005,53(3-4):231-236
The phase diagram of the pyridine–iron(III) chloride system has been studied for the 223–423 K temperature and 0–56 mass-% concentration ranges using differential thermal analysis (DTA) and solubility techniques. A solid with the highest pyridine content formed in the system was found to be an already known clathrate compound, [FePy3Cl3]·Py. The clathrate melts incongruently at 346.9 ± 0.3 K with the destruction of the host complex: [FePy3Cl3]·Py(solid)=[FePy2Cl3](solid) + liquor. The thermal dissociation of the clathrate with the release of pyridine into the gaseous phase (TGA) occurs in a similar way: [FePy3Cl3]·Py(solid)=[FePy2Cl3](solid) + 2 Py(gas). Thermodynamic parameters of the clathrate dissociation have been determined from the dependence of the pyridine vapour pressure over the clathrate samples versus temperature (tensimetric method). The dependence experiences a change at 327 K indicating a polymorphous transformation occurring at this temperature. For the process ${1 \over 2}[\hbox{FePy}_{3}\hbox{Cl}_{3}]\cdot \hbox{Py}_{\rm (solid)} = {1 \over 2}[\hbox{FePy}_{2}\hbox{Cl}_{3}]_{\rm (solid)} + \hbox{Py}_{\rm (gas)}$ in the range 292–327 K, ΔH $^{0}_{298}$ =70.8 ± 0.8 kJ/mol, ΔS $^{0}_{298}$ =197 ± 3 J/(mol K), ΔG $^{0}_{298}$ =12.2 ± 0.1 kJ/mol; in the range 327–368 K, ΔH $^{0}_{298}$ =44.4 ± 1.3 kJ/mol, ΔS $^{0}_{298}$ =116 ± 4 J/(mol K), ΔG $^{0}_{298}$ =9.9 ± 0.3 kJ/mol. 相似文献
6.
Kurnosov AV Ogienko AG Goryainov SV Larionov EG Manakov AY Lihacheva AY Aladko EY Zhurko FV Voronin VI Berger IF Ancharov AI 《The journal of physical chemistry. B》2006,110(43):21788-21792
Dissociation temperatures of gas hydrate formed in the ethane-water system were studied at pressures up to 1500 MPa. In situ neutron diffraction analysis and X-ray diffraction analysis in a diamond anvil cell showed that the gas hydrate formed in the ethane-water system at 340, 700, and 1840 MPa and room temperature belongs to the cubic structure I (CS-I). Raman spectra of C-C vibrations of ethane molecules in the hydrate phase, as well as the spectra of solid and liquid ethane under high-pressure conditions were studied at pressures up to 6900 MPa. Within 170-3600 MPa Raman shift of the C-C vibration mode of ethane in the hydrate phase did not show any discontinuities, which could be evidence of possible phase transformations. The upper pressure boundary of high-pressure hydrate existence was discovered at the pressure of 3600 MPa. This boundary corresponds to decomposition of the hydrate to solid ethane and ice VII. The type of phase diagram of ethane-water system was proposed in the pressure range of hydrate formation (0-3600 MPa). 相似文献
7.
Soldatov D. V. Suwinska K. Lipkowski J. Ogienko A. G. 《Journal of Structural Chemistry》1999,40(5):781-789
Journal of Structural Chemistry - The structure of the [CuPy4(NO3)2] complex (Py = pvridine) and its clathrates with tetrahydrofuran and chloroform (both with a host:guest molar ratio of 1:2) were... 相似文献
8.
A. A. Ogienko S. A. Myz E. V. Boldyreva E. G. Zevak A. G. Ogienko A. Yu. Manakov A. I. Ancharov B. M. Kuchumov A. A. Krasnikov 《Bulletin of the Russian Academy of Sciences: Physics》2014,78(9):868-873
Detailed study and understanding of the processes that occur during the cooling and subsequent annealing of frozen solutions of drugs in two-component systems of low boiling point liquids and water with clathrate formation requires the active involvement of scanning electron microscopy (SEM) to select the optimum conditions for freeze drying and comparative analysis of samples, forms of dosage, and initial substances. A new way of creating ultrafine forms of drugs and pharmaceutical compositions by freeze drying that can easily be extended to almost all modern low-dosage drugs to improve their pharmacokinetic profile and technological properties is developed. 相似文献
9.
Dr. Andrey Yu. Manakov Dr. Anna Yu. Likhacheva Dr. Vladimir A. Potemkin Dr. Andrey G. Ogienko Dr. Alexander V. Kurnosov Dr. Aleksei I. Ancharov 《Chemphyschem》2011,12(13):2476-2484
Experimental data on the pressure dependence of unit cell parameters for the gas hydrates of ethane (cubic structure I, pressure range 0–2 GPa), xenon (cubic structure I, pressure range 0–1.5 GPa) and the double hydrate of tetrahydrofuran+xenon (cubic structure II, pressure range 0–3 GPa) are presented. Approximation of the data using the cubic Birch–Murnaghan equation, P=1.5B0[(V0/V)7/3?(V0/V)5/3], gave the following results: for ethane hydrate V0=1781 Å3, B0=11.2 GPa; for xenon hydrate V0=1726 Å3, B0=9.3 GPa; for the double hydrate of tetrahydrofuran+xenon V0=5323 Å3, B0=8.8 GPa. In the last case, the approximation was performed within the pressure range 0–1.5 GPa; it is impossible to describe the results within a broader pressure range using the cubic Birch–Murnaghan equation. At the maximum pressure of the existence of the double hydrate of tetrahydrofuran+xenon (3.1 GPa), the unit cell volume was 86 % of the unit cell volume at zero pressure. Analysis of the experimental data obtained by us and data available from the literature showed that 1) the bulk modulus of gas hydrates with classical polyhedral structures, in most cases, are close to each other and 2) the bulk modulus is mainly determined by the elasticity of the hydrogen‐bonded water framework. Variable filling of the cavities with guest molecules also has a substantial effect on the bulk modulus. On the basis of the obtained results, we concluded that the bulk modulus of gas hydrates with classical polyhedral structures and existing at pressures up to 1.5 GPa was equal to (9±2) GPa. In cases when data on the equations of state for the hydrates were unavailable, the indicated values may be recommended as the most probable ones. 相似文献
10.
N. A. Pushkarevsky M. A. Ogienko N. V. Kuratieva S. N. Konchenko 《Russian Chemical Bulletin》2008,57(1):36-39
The reaction of the [Fe2(CO)6(μ-S)2]2? anion (prepared in situ by reduction of [Fe2(CO)6(μ-S2)] with Na/K alloy) with [Cp″RhCl2]2 (Cp″ = η5-(1,3-But 2)C5H3) and [Cp*Ir(CH3CN)3](CF3SO3)2 (Cp* is pentamethylcyclopentadienide) yielded new heterometallic clusters [Fe2(MCp x )(CO)6(μ3-S)2]. The core of the resulting clusters can be described as the distorted [Fe2S2M] square pyramid with the M atom in the apical position. The structures of the clusters were established by X-ray diffraction. 相似文献