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91.
K. N. Semenov N. A. Charykov V. A. Keskinov 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2013,87(1):54-57
Synthesis of the piperidine, pyrrolidine, and morpholine derivatives of fullerene C60 and their identification by electronic and IR spectroscopy were reported. The solubility of these derivatives in benzene at temperatures from 20 to 80°C was studied. 相似文献
92.
Elena A. Shalamova Yeosan Lee Garam Chung Artem N. Semakin Jinho Oh Alexey Yu. Sukhorukov Dmitry E. Arkhipov Sema L. Ioffe Sergey E. Semenov 《Tetrahedron letters》2014
A general strategy for the assembly of previously unknown tris(β,β,γ-oximinoalkyl)amines from aliphatic nitro compounds and methyl vinyl ketone is described. The strategy involves N,N-bis(siloxy)enamines as key intermediates. The latter are accessible by double silylation of alkylnitro compounds. Nickel(II) and copper(II) complexes of tris(β,β,γ-oximinoalkyl)amines are prepared and structurally characterized. 相似文献
93.
Mikolaichuk O. V. Protas A. V. Popova E. A. Molchanov O. E. Maistrenko D. N. Ostrovskii V. A. Pavlyukova Yu. N. Sharoyko V. V. Semenov K. N. 《Russian Journal of General Chemistry》2022,92(9):1621-1628
Russian Journal of General Chemistry - New tetrazole-containing derivatives of 2,4-diamino-1,3,5-triazine were synthesized. The cytotoxic activity of the obtained compounds against Huh-7 and HeLa... 相似文献
94.
Andreeva O. V. Saifina L. F. Belenok M. G. Semenov V. E. Kataev V. E. 《Russian Journal of Organic Chemistry》2021,57(2):292-296
Russian Journal of Organic Chemistry - The reaction of 1,5-bis[1-(prop-2-yn-1-yl)uracil-3-yl]pentane with 2',3',5'-tri-O-acetyl-β-d-ribofuranosylazide followed by removing of... 相似文献
95.
Semenov S. G. Makarova M. V. Bedrina M. E. Titov A. V. 《Russian Journal of General Chemistry》2021,91(3):389-392
Russian Journal of General Chemistry - A quantum-chemical model of the minimal cluster in xenotime has been proposed taking into account the ionic-crystal medium potential. The [YO8]5–... 相似文献
96.
Living polymers are formed by reversible association of primary units (unimers). Generally the chain statistical weight involves
a factor σ < 1 suppressing short chains in comparison with free unimers. Living polymerization is a sharp thermodynamic transition
for σ ≪ 1 which is typically the case. We show that this sharpness has an important effect on the kinetics of living polymerization
(one-dimensional association). The kinetic model involves i) the unimer activation step (a transition to an assembly-competent
state); ii) the scission/recombination processes providing growth of polymer chains and relaxation of their length distribution.
Analyzing the polymerization with no chains but unimers at t = 0 , with initial concentration of unimers M ≳ M
* (M* is the critical polymerization concentration), we determine the time evolution of the chain length distribution and find
that: 1) for M
* ≪ M ≪ M
*/σ the kinetics is characterized by 5 distinct time stages demarcated by 4 characteristic times t1, t2, t3 and t*; 2) there are transient regimes (t
1 ≲ t ≲ t
3) when the molecular-weight distribution is strongly non-exponential; 3) the chain scissions are negligible at times shorter
than t2. The chain growth is auto-accelerated for t
1 ≲ t ≲ t
2 : the cut-off chain length (= polymerization degree 〈n〉w
N
1 ∝ t
2 in this regime. 4) For t
2 < t < t
3 the length distribution is characterized by essentially 2 non-linear modes; the shorter cut-off length N1 is decreasing with time in this regime, while the length scale N2 of the second mode is increasing. (5) The terminal relaxation time of the polymer length distribution, t*, shows a sharp maximum in the vicinity of M*; the effective exponent
is as high as ∼ σ-1/3 just above M*. 相似文献
97.
A. Savitsky B. V. Trubitsin K. Möbius A. Yu. Semenov A. N. Tikhonov 《Applied magnetic resonance》2007,31(1-2):221-236
In this work, by using the respective advantages of W- and X-band electron paramagnetic resonance (EPR) spectroscopy techniques to investigate electron transport processes, we have studied the light-induced redox transients of the primary electron donor P700 and the secondary acceptor A1 in photosystem (PS) I complexes of intact cyanobacterial cellsSynechocystis sp. PCC 6803. We found that the kinetic behavior of the cation radical P700 ·+ generated by illumination with continuous light, and the EPR intensity of the radical pair P700 ·+A 1 ·? generated upon laser pulse illumination strongly depend on the illumination prehistory (either the sample was frozen in the dark or during illumination). Both these processes were sensitive to the presence of electron transport inhibitors which block electron flow between the two photosystems. In line with our X-band EPR data on the kinetics of light-induced redox transients of P700, our high-field W-band EPR study of the radical-pair state P700 ·+A 1 ·? shows that photosynthetic electron flow through the PS I reaction center is controlled both on the donor and on the acceptor side of PS I. 相似文献
98.
A. A. Semenov D. V. Feoktistov D. V. Zaitsev G. V. Kuznetsov O. A. Kabov 《Thermophysics and Aeromechanics》2015,22(6):771-774
Evaporation of a water drop was studied experimentally at a temperature difference between the solid surface and surrounding atmosphere from 30 to 60 °C. The studies were performed on the substrates with micro- and nanocoatings with different wettability. The features of evaporation were studied for the pinned, partially pinned, and depinned three-phase contact line (solid-liquid?gas interface). It is shown that with a decrease in the water drop volume, the specific evaporation rate (mass flow per unit of surface area) increases, particularly at the last stage of evaporation. 相似文献
99.
According to the results of PBE0/cc-pVTZ quantum chemical calculations, the equilibrium mixture of α-diazocarbonyl bullvalene derivatives (C10H8N2O) contains an impurity of the corresponding bullvaleno-[1,2,3]oxadiazoles. The carbonyl group in the major tautomer is conjugated with the three-membered ring. The concentration of other tautomers in the equilibrium mixture of two bullvaleno[1,2,3]selenadiazoles is negligible. 相似文献
100.
Using the quantum chemical method PBE0/cc-pVTZ, we determined structural parameters and dipole moments of bullvalene (tricyclo[3.3.2.04.6]deca-2,7,9-triene), 1-, 2-, 3-, and 4-hydroxytricyclo[3.3.2.04.6]-deca-2,7,9-trienes, and isomeric 2- and 3-ketones transforming into each other through the keto-enol tautomerism and Cope rearrangement with the triatomic ring migration. The dominant tautomer is 3-ketone containing a triatomic ring conjugated with the carbonyl group. 相似文献