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11.
N. S. Vul'fson V. A. Puchkov Yu. V. Denisov B. V. Rozynov V. N. Bochkarev M. M. Shemyakin Yu. A. Ovchinnikov V. K. Antonov 《Chemistry of Heterocyclic Compounds》1967,2(4):468-474
Analysis of mass-spectra of various 2, 5-diketopiperazines gives the basic fragmentation rules for their molecular ions, and the effects of nature and positions of substituents on the process.Mass-spectrometry Laboratory of the Institute of the Chemistry of Natural Compounds.Antibiotics Chemistry Laboratory of the Institute of the Chemistry of Natural Compounds. 相似文献
12.
E. I. Burmakin S. S. Stroev G. Sh. Shekhtman B. D. Antonov 《Russian Journal of Electrochemistry》2003,39(9):1005-1007
Solid solutions Cs3 – 2x
M
x
PO4 (M = Ba, Sr, Ca, Mg) are synthesized and their thermal behavior and electroconductivity are examined. Adding elements of Subgroup IIA of the periodic table into cesium orthophosphate shifts the phase transition, which occurs in pure Cs3PO4 at 450–620°, towards lower temperatures and raises the cesium cation conductivity at low temperatures. The electroconductivity of a high-temperature modification of Cs3PO4 is weakly dependent on the presence and concentration of such additives, which points to structural disordering of the cesium sublattice. 相似文献
13.
Abe K Akagi T Anthony PL Antonov R Arnold RG Averett T Band HR Bauer JM Borel H Bosted PE Breton V Button-Shafer J Chen JP Chupp TE Clendenin J Comptour C Coulter KP Court G Crabb D Daoudi M Day D Dietrich FS Dunne J Dutz H Erbacher R Fellbaum J Feltham A Fonvieille H Frlez E Garvey D Gearhart R Gomez J Grenier P Griffioen KA Hoibraten S Hughes EW Hyde-Wright C Johnson JR Kawall D Klein A Kuhn SE Kuriki M Lindgren R Liu TJ Lombard-Nelsen RM Marroncle J Maruyama T Maruyama XK McCarthy J Meyer W 《Physical review letters》1995,74(3):346-350
14.
I. L. Odinets O. I. Artyushin E. A. Antonov P. V. Petrovskii B. I. Freger T. A. Mastryukova M. I. Kabachnik 《Russian Chemical Bulletin》1994,43(1):121-124
It was shown by31P and13C NMR spectroscopy that methyl(3-carboxy-3-oxopropyl)phosphinic acid (4-methylhydroxyphosphinyl-2-oxobutyric acid) (1) and the amide (2) of the latter exist in keto forms in non-aqueous solutions. In aqueous solutions an equilibrium between the keto,gem-diol, and enol forms has been observed. The proportions of the diol and enol forms increase as the acidity of the media increases. Silylation of acid 1 with hexamethyldisilazane gives the tris(trimethylsilyl) derivative of enol form (3) (Z- andE-isomers).Translated fromIzyestiya Akadetnii Nauk. Seriya Khimicheskaya, No. 1, pp. 125–128, January, 1994. 相似文献
15.
The temperature dependences of the equilibrium constants of two chain reversible reactions in quinonediimine (quinonemonoimine)—2,5-dichlorohydroquinone
systems in chlorobenzene were studied. The enthalpy of equilibrium of the reversible reaction of quinonediimine with 4-hydroxydiphenylamine
was estimated from these data (ΔH = − 14.4±1.6 kJ mol−1) and a more accurate value of the N-H bond dissociation energy in the 4-anilinodiphenylaminyl radical was determined (D
NH = 278.6±3.0 kJ mol−1). A chain mechanism was proposed for the reaction between quinonediimine and 2,5-dichlorohydroquinone, and the chain length
was estimated (ν = 300 units) at room temperature. Processing of published data on the rate constant of the reaction of styrylperoxy
radicals with 2,5-dichlorohydroquinone in the framework of the intersecting parabolas method gave the O-H bond dissociation
energy in 2,5-dichlorohydroquinone: D
OH = 362.4±0.9 kJ mol−1. Taking into account these data, the O-H bond dissociation energy in the 2,5-dichlorosemiquinone radical was found: D
OH = 253.6±1.9 kJ mol−1.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1661–1666, October, 2006. 相似文献
16.
The synthesis has been effected of the amide of the tetrapeptide forming the sequence 6–9 of oxytocin with the use of benzyl protection of the thiol function of cysteine by two main schemes 1+3 and 2+2. The advantageousness of performing the synthesis by the 2+2 scheme has been shown. The overall yield of tetrapeptide using the method of condensation with the formation of mixed anhydrides amounted to 51% by the scheme proposed.All-Union Scientific-Research Institute of the Technology of Blood Substitutes and Hormone Preparations, Moscow. Translated from Khimiya Prirodnykh Soedinenii, Nos. 3,4, pp. 393–400, May–August, 1992. 相似文献
17.
K. Laihia A. Valkonen E. Kolehmainen A. Antonov D. Zhukov I. Fedosov V. Nikiforov 《Journal of Molecular Structure》2006,800(1-3):100-105
Three spiro[pyrrolidine-2,3′-oxindoles], 1,1′,2,2′,5′,6′,7′,7′a-octahydro-2-oxo-1′-phenyl-spiro[3H-indole-3,3′-[3H]-pyrrolizine]-2′-carboxylic acid methyl ester (1), 1,1′,2,2′,5′,6′,7′,7′a-octahydro-2-oxo-1′-nitro-2′-phenyl-spiro[3H-indole-3, 3′-[3H]-pyrrolizine] (2) and 1,1′,2,2′,5′,6′,7′,7′a-octahydro-2-oxo-1′-nitro-2′-(4″-chlorophenyl)-spiro[3H-indole-3,3′-[3H]-pyrrolizine] (3) have been synthesized and their 1H, 13C and 15N spectra assigned. The chemical shift assignments are based on Pulsed Field Gradient (PFG) Double Quantum Filter (DQF) 1H, 1H correlation spectroscopy (COSY), PFG 1H, 13C Heteronuclear Multiple Quantum Coherence (HMQC) and PFG 1H,X (X = 13C and 15N) Heteronuclear Multiple Bond Correlation (HMBC) experiments. The single crystal X-ray structures of 1–3 have been determined. Compounds 1 and 2 crystallized in monoclinic space group C2/c and compound 3 in monoclinic space group P21/c, respectively. Also the ESI-TOF MS data of 1–3 are given. 相似文献
18.
Russian Journal of Applied Chemistry - xWO3–(100–x)P2O5 (70 mol % ≤ x ≤ 82 mol %) glasses were obtained by melt quenching. Their thermal properties were studied by the DTA... 相似文献
19.
I. D. Zakir’yanova I. V. Korzun V. A. Khokhlov V. N. Dokutovich E. V. Nikolaeva B. D. Antonov 《Russian Journal of Applied Chemistry》2016,89(7):1066-1071
Data on reactivities of α- and γ-Al2O3 finely dispersed powders in a melted carbonate eutectic (Li2CO3–Na2CO3–K2CO3)eut and carbonate-chloride mixture 0.72(Li2CO3–Na2CO3–K2CO3)eut–0.28NaCl were obtained. The methods of synchronous thermal and X-ray phase analyses and Raman spectroscopy confirmed that, in contrast to γ-Al2O3, α-Al2O3 does not chemically interact with the melted carbonate eutectic and carbonate-chloride mixture (Li2CO3–Na2CO3–K2CO3)eut–NaCl can be recommended as a thickening agent for a carbonate fuel cell. 相似文献
20.
V. F. Kablov N. A. Keibal V. G. Kochetkov A. O. Motchenko Yu. M. Antonov 《Russian Journal of Applied Chemistry》2018,91(7):1160-1164
The influence of carbon microfiber on the physicomechanical, thermophysical, and fireproof characteristics of elastomeric compositions based on ethylene propylene diene rubber is considered. Microfibrous filler contributes to the manifestation of the effect of “micro-reinforcement,” which leads to an increase in the heatprotective properties of the material due to the increase in the strength of coke. The correction of microfibers with a phosphorus-boron-containing oligomer enhances the carbonization of the material, which leads to an increase in the warming-up time of the unheated sample surface by 8–10% and a decrease in the linear combustion rate by 10–15% compared to known analogues. 相似文献