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31.
Kuvychko IV Streletskii AV Popov AA Kotsiris SG Drewello T Strauss SH Boltalina OV 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(18):5426-5436
Three previously reported procedures for the synthesis of pure C(s)-C60Cl6 from C60 and ICl dissolved in benzene or 1,2-dichlorobenzene were shown to actually yield complex mixtures of products that contain, at best, 54-80% C(s)-C60Cl6 based on HPLC integrated intensities. MALDI mass spectrometry was used for the first time to identify other components of the reaction mixtures. An improved synthetic procedure was developed for the synthesis of about 150 mg batches of chlorofullerenes containing 90% C(s)-C60Cl6 based on HPLC intensities. The optimum reaction time was decreased from several days to seven minutes. Small amounts of the product were purified by HPLC (toluene eluent) to 99% purity. The pure compound C(s)-C60Cl6 is stable for at least three months as a solvent-free powder at 25 degrees C. The Raman, far-IR, and MALDI mass spectra of pure C(s)-C60Cl6 are reported for the first time. The Raman and far-IR spectra, the first reported for any C60Cl(n) chlorofullerene, were used to carry out a vibrational analysis of C(s)-C60Cl6 at the DFT level of theory. 相似文献
32.
A. Yu. Dolgoborodov A. N. Streletskii M. N. Makhov I. V. Kolbanev V. E. Fortov 《Russian Journal of Physical Chemistry B, Focus on Physics》2007,1(6):606-611
Detonation-like regimes in mechanoactivated energetic composites (MAECs) were experimentally studied. The test MAECs consisted of layers of a metal (Al, Mg) and Teflon mixed at the submicron and nano levels. The systems reacted to form solid final products. MAECs are appreciably superior to ordinary mixtures in chemical transformation rate. The burning of MAECs occurs in an explosive regime at a velocity of 300–400 m/s, with the temperature of the products being as high as 4000 K. When initiated with a HE charge, porous MAECs detonate in the steady regime. Depending on the composition and density of the samples, the detonation velocity varies from 700 to 1300 m/s, values markedly higher than the speed of sound in the initial mixture. Detonation is controlled by a hot spot mechanism, more specifically, by relay reaction propagation by jets of products. 相似文献
33.
Mechanochemical activation of aluminum. 4. Kinetics of mechanochemical synthesis of aluminum carbide
A. N. Streletskii I. V. Povstugar A. B. Borunova S. F. Lomaeva P. Yu. Butyagin 《Colloid Journal》2006,68(4):470-480
The kinetics of mechanochemical synthesis of aluminum carbide Al4C3 from elements was studied with X-ray diffraction analysis, low-temperature argon adsorption, laser granulometry, chemical analysis, X-ray photoelectron spectroscopy, and electron scanning microscopy. The conversion was presented as a function of energy consumption (dose) upon the mechanical treatment of mixtures of aluminum and graphite powders with the composition Al-15 wt % C and Al-30 wt % C. A multistage mechanism of the mechanochemical reaction was revealed, and the following stages were separated and characterized: (i) independent grinding and mixing of reagents, (ii) formation of molecular-dense Al/C composites based on nanosized aluminum particles, (iii) chemical interaction of components with the formation of interatomic Al-C bonds, and (iv) crystallization of Al4C3 carbide. The formation of amorphous nuclei of aluminum carbide occurs on the contact surface of aluminum nanoparticles with carbon. 相似文献
34.
A. N. Streletskii S. N. Mudretsova I. V. Povstugar P. Yu. Butyagin 《Colloid Journal》2006,68(5):623-631
The mechanical activation of thermal synthesis of aluminum carbide Al4C3 in Al-15 wt % C and Al-30 wt % C mixtures is studied with differential scanning calorimetry, X-ray diffraction, and transmission electron microscopy. It is found that the mechanical treatment of powders results in an essential reduction in the temperature of carbide synthesis. A correlation between the temperature of the onset of synthesis and size L of the coherent scattering region of aluminum is established. When the doses of absorbed mechanical energy exceed 15–20 kJ/g and, as a result, the L value decreases to 20 nm, the synthesis proceeds by a solid-phase mechanism at a temperature significantly lower than the melting point of aluminum and the synthesis temperature reduces by 800°C. The particle size of the formed aluminum carbide and unreacted aluminum after heating to 900°C is 20–40 nm. At doses D = 50–80 kJ/g, the heat of the formation of carbide from activated samples is about two times lower compared to the standard value. The possible sources of this discrepancy are discussed. 相似文献
35.
A. N. Streletskii I. V. Kolbanev A. B. Borunova A. V. Leonov P. Yu. Butyagin 《Colloid Journal》2004,66(6):729-735
Changes in the crystal structure and composition of aluminum and graphite powder mixtures in the course of their joint mechanical treatment in a vibration mill were monitored by the adsorption and X-ray diffraction techniques. It was shown that, at absorbed energy doses of 8–10 kJ/g, the grinding and mixing of aluminum with graphite is completed by the formation of an intermediate structure of Al/C composite, where aluminum showed an anomalously high reactivity. The interaction of aluminum with water was used to study its reactivity in the composite. The formation of the composite preceded the stage of chemical interaction between carbon and aluminum atoms.Translated from Kolloidnyi Zhurnal, Vol. 66, No. 6, 2004, pp. 811–818.Original Russian Text Copyright © 2004 by Streletskii, Kolbanev, Borunova, Leonov, Butyagin. 相似文献
36.
Zavidovskii I. A. Streletskii O. A. Nishchak O. Yu. Khaidarov A. A. Pavlikov A. V. 《Technical Physics》2020,65(1):139-144
Technical Physics - Carbon films with different extents of sp hybridization have been grown by ion–plasma pulsed arc sputtering of graphite in a methane atmosphere. Using Raman scattering and... 相似文献
37.
Zavidovskii I. A. Streletskii O. A. Nishchak O. Yu. Khaidarov A. A. 《Physics of the Solid State》2019,61(11):2228-2232
Physics of the Solid State - Thin carbon films prepared by pulsed plasma ion-assisted deposition of graphite in an atmosphere of a mixture of argon and nitrogen are studied. The results of... 相似文献
38.
Bruno C Marcaccio M Paolucci D Castellarin-Cudia C Goldoni A Streletskii AV Drewello T Barison S Venturini A Zerbetto F Paolucci F 《Journal of the American Chemical Society》2008,130(12):3788-3796
The formidable electron-acceptor properties of C60 contrast with its difficult oxidations. Only recently it has become possible to achieve reversibility of more than one electrochemical anodic process versus the six reversible cathodic reductions. Here we exploit the reactivity of electrochemical oxidations of pure C60 to grow a film of high thermal and mechanical stability on the anode. The new material differs remarkably from its precursor since it conducts both electrons and holes. Its growth and properties are consistently characterized by a host of techniques that include atomic force microscopy (AFM), Raman and infrared spectroscopies, X-ray-photoelectron spectroscopy (XPS), secondary-ion mass spectrometry (SIMS), scanning electron microscopy and energy-dispersive X-ray analysis (SEM-EDX), matrix-assisted laser desorption/ionization (MALDI), and a variety of electrochemical measurements. 相似文献
39.
A. F. Aleksandrov O. A. Streletskii V. V. Khvostov A. V. Faustov N. D. Novikov A. A. Zaitsev 《Moscow University Physics Bulletin》2012,67(6):528-531
Results are presented from investigations into the conductivity of heterostructures based on two-dimensionally ordered (TDO) linear-chain carbon (LCC) in the form of Al-LCC-Al and pSi-LCC-Al. The Al-LCC-Al structure is shown to possess a nonlinear ohmic contact with a barrier height of around 0.7 eV. It is shown that an over-barrier (Schottky) mechanism of electron injection to LCC in the forward direction and a tunneling effect (Fowler-Nordheim tunnel injection mechanism) in the backward direction occur in the pSi-LCC-Al heterostructure. 相似文献
40.
Vasil'ev YV Khvostenko OG Streletskii AV Boltalina OV Kotsiris SG Drewello T 《The journal of physical chemistry. A》2006,110(18):5967-5972
DCTB [(H(3)C)(3)C-p-Ph-CH=C(CH(3))-trans-CH=C(CN)(2)] has recently advanced to the most promising matrix material for matrix-assisted laser desorption/ionization (MALDI) within material sciences. However, data that would allow the evaluation of the electron-transfer reactivity within a thermochemical framework are sparse. The present study reports the first-time determination of the ionization energy (IE) of DCTB applying photoelectron (PE) spectroscopy. The experimental IE (8.54 +/- 0.05 eV) is in excellent agreement with the theoretical value of 8.47 eV, obtained by AM1 calculations. The same level of theory determines the electron affinity (EA) as 2.31 eV. Model analytes of known thermochemistry (phenanthrene [C(14)H(10)], anthracene [C(14)H(10)] and fluorofullerene [C(60)F(46/48)]) are used to bracket the electron-transfer reactivity within DCTB-MALDI. The formation of molecular ions of these analytes either is expected or is beyond the thermochemical accessibility of the DCTB matrix. 相似文献