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31.
Two polymorphic modifications of (BEDT-TTF)2IC12 crystals with metallic and semiconductor properties
Buravov L. I. Zvarykina A. V. Ignat'ev A. A. Kotov A. I. Laukhin V. N. Makova M. K. Merzhanov V. A. Rozenberg L. P. Shibaeva R. P. Yagubskii É. B. 《Russian Chemical Bulletin》1988,37(9):1815-1820
1. | By chemical and electrochemical methods we have obtained as single crystals two polymorphic modifications ( and ') of the radical-cation salt of composition (BEDT-TTF)2IC12. |
2. | We have studied the electrical conductivity, the thermoelectric and magnetic properties of both phases. We have found that the phase is a metal (293 – 200 ohm–1.cm–1) and the ' phase is a semiconductor (293 –= 10–2 ohm–1 · cm–1). |
3. | We have established correlations between the structural and physical properties of - and '-(BEDT-TTF)2ICl2. |
32.
Regularities of hole transport and its correlation with percolation magnetism caused by localized carriers simultaneously involved in the formation of the magnetic and electrical properties of Ge: Mn thin films are investigated. It is established that at temperatures of T > 22 K the activationless band carrier transport occurs in the Ge: Mn samples (2 at % Mn). At low temperatures, the hopping mechanism with a variable hopping length works. 相似文献
33.
O. N. Kazheva G. G. Aleksandrov A. V. Kravchenko V. A. Starodub G. G. Zhigareva I. B. Sivaev V. I. Bregadze L. I. Buravov L. V. Titov O. A. D’yachenko 《Russian Chemical Bulletin》2010,59(6):1137-1144
The radical cation salts of tetrathiafulvalene (TTF) and bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) with iodo derivatives
of cobalt bis(dicarbollide), (TTF)[9,9′,12,12′-I4-3,3′-Co(1,2-C2B9H9)2] and (BEDT-TTF)[9,9′(12′)-I2-3,3′-Co(1,2-C2B9H10)2], respectively, were synthesized and their crystal structures were determined. The introduction of iodine atoms into the
lower rim of the dicarbollide ligands, unlike the substitution at the upper rim, leads to insignificant changes in the crystal
structure and the conductivity of the radical cation salts compared to the analogous salts based on unsubstituted cobalt bis(dicarbollide). 相似文献
34.
Erik Čižmár Daniela Šoltésová Olga N. Kazheva Grigorii G. Alexandrov Andrey V. Kravchenko Lyubov A. Chekulaeva Irina D. Kosenko Igor B. Sivaev Vladimir I. Bregadze Alexey V. Fedorchenko Vladimir A. Starodub Lev I. Buravov Oleg A. Dyachenko Alexander Feher 《Transition Metal Chemistry》2018,43(7):647-655
The synthesis of a radical-cation salt based on a derivative of tetrathiafulvalene, (ET)2[3,3′-Cr(1,2-C2B9H11)2] (ET?=?bis(ethylenedithio)tetrathiafulvalenium), was accomplished by electrochemical anodic oxidation of ET in the presence of (Me4N)[3,3´-Cr(1,2-C2B9H11)2] in the galvanostatic regime. An electric conductivity σ (293 K)?=?7 × 10?3 Ohm?1 cm?1 with semiconductor activation energy Ea???0.1 eV in the range of 127–300 K was observed. The crystal structure of (ET)2[3,3′-Cr(1,2-C2B9H11)2] was determined by X-ray diffraction at 173 K, revealing the presence of structural tetramers in radical-cation stacks. The magnetic properties of the complex were investigated in the temperature range 1.8–300 K using magnetometry and EPR, showing that the magnetic structure of (ET)2[3,3′-Cr(1,2-C2B9H11)2] consists of two independent magnetic subsystems. Cation radicals form a rectangular magnetic lattice in the ab-plane with significant antiferromagnetic exchange interactions. The chromium bis(dicarbollide) anions are characterized by unusually strong positive zero-field splitting of the Cr(III) ions, which was confirmed by ab initio calculations. 相似文献
35.
36.
L. I. Buravov O. A. D'yachenko S. V. Konovalikhin N. D. Kushch I. P. Lavrent'ev N. G. Spitsyna G. V. Shilov E. B. Yagubskii 《Russian Chemical Bulletin》1994,43(2):240-244
The C60·2S8 complex was prepared by reaction of buckminsterfullerene C60 with sulfur in trichloroethylene and its single-crystal X-ray structure was studied at room temperature. Crystals of this compound are monoclinic, space groupC 2/c, a=20.90(1),b=21.10(1),c=10.537(9) Å, =111.29(7)°,Z=4,d
calc=1.89 g·cm–3. The crystal structure of the C60·2S8 complex consists of packed fullerene molecules that form hexagonal channels along thec axis with eight-membered crown-shaped S8 cyclic molecules inside the channels. The distances between the centers of neighboring fullerene molecules are 10.036(7), 10.636(7), and 10.537(9) Å. Each C60 molecule is linked to eight S8 molecules with ten shortened intermolecular contacts C...S 3.41(1)–3.52(2) Å. The average values of the C=C and C-C bond lengths are 1.32(3) and 1.47(3) Å, which attest to a significant degree of localization of electron density in the c60 molecule.Translated from Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 262–266, February, 1994. 相似文献
37.
A. S. Lobach L. I. Buravov N. G. Spitsyna A. V. Eletskii A. P. Dementjev K. I. Maslakov 《High Energy Chemistry》2011,45(4):328-334
Electrical resistance of films made of the source material and purified HiPCO and Arc single-walled carbon nanotubes (SWCNTs)
with a thickness of 20−40 μm is 2.4 to 45 Ω (electrical conductivity of 0.42 × 103 to 5.03 × 103 S/m) at room temperature. The films have been formed by vacuum microfiltration of SWCNT suspensions in toluene and characterized
by Raman and X-ray photoelectron spectroscopy and scanning electron microscopy. The conductivity of the films at room temperature
depends on the type and degree of purity of the material of nanotubes. The resistance of the films decreases with the increasing
temperature over the range of 4.2–290 K, and the rate of the step-down decreases with increasing purity of the material of
the nanotubes. The conductivity of the films is semiconducting in character, and the electron transport is consistent with
three-dimensional hopping conductivity. 相似文献