排序方式: 共有19条查询结果,搜索用时 9 毫秒
1.
Savos'kin M. V. Yaroshenko A. P. Mysyk R. D. Vaiman G. E. Vovchenko L. L. Popov A. F. 《Theoretical and Experimental Chemistry》2004,40(2):92-97
New thermally stable intercalation compounds of graphite were obtained by the further intercalation of a series of organic compounds into graphite nitrate. The stabilization is explained by the formation of hydrogen bonds between the protonated form of the modifying substance and neutral surrounding molecules. 相似文献
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A. P. Yaroshenko M. V. Savos’kin V. I. Shologon R. D. Mysyk A. N. Magazinskii 《Russian Journal of Applied Chemistry》2006,79(1):163-165
The possibility of obtaining residual graphite nitrate by water treatment of graphite nitrate and its subsequent drying was studied. The expansion coefficients were determined in the temperature range 500–900°C with a step of 100°C for the samples obtained. 相似文献
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I. V. Kurdyukova N. A. Derevyanko A. A. Ishchenko D. D. Mysyk 《Russian Journal of General Chemistry》2012,82(4):703-719
The di-, tetra- and hexamethine merocyaninyes, the derivatives of fluorene, diphenyl 9H-fluorene-2,7-disulfonate, and bis(2,2,3,3,4,4,5,5-octafluoropentyl) 9H-fluorene-2,7-disulfonate, as well as the derivatives of the heterocycles of moderate (indolylidene and benzotiazolylidene), weak (benzo[c,d]indolylidene and 2,6-diphenylpyrane) and strong (2,6-diphenylpyridine) electron-donor properties were synthesized and their absorption spectra in solvents of different polarity were studied. The quantum-chemical analysis of electronic structure of the synthesized merocyanines was performed and the types of electronic transitions in them were found by the DFT and TDDFT methods with the B3LYP/6-31G(d,p) basis. 相似文献
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I. V. Kurdyukova N. A. Derevyanko A. A. Ishchenko D. D. Mysyk 《Russian Chemical Bulletin》2012,61(2):287-297
Novel anionic polymethine dyes were synthesized from 2,7-bis(phenoxysulfonyl)-, 2,7-dinitro-, and 2,4,5,7-tetranitrofluorenes. The reasons for the complicated shape of their absorption spectra were analyzed: the formation of contact ion pairs, associates, and conformational isomers and electronic effects of substituents. The quantum chemical calculations by the Pariser??Parr??Pople method and nonempirical DFT and TDDFT methods in the B3LYP/6-31G(d,p) basis set revealed that the orbitals of the nitro groups, unlike the orbitals of the SO2OPh groups, are efficiently conjugated with the common chromophore system inducing additional electron transitions. 相似文献
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I. V. Kurdyukova N. A. Derevyanko A. A. Ishchenko D. D. Mysyk 《Russian Chemical Bulletin》2009,58(4):828-837
Anionic symmetric polymethine dyes have been synthesized based on bis(2,2,3,3,4,4,5,5-octafluoropentyl) 9H-fluorene-2,7-disulfonate,
which exhibit intensive absorption in the near IR region of the spectrum: pentamethine with an open polymethine chain (⋉max = 790 nm) and nonamethine with six- and five-membered saturated rings at δ-positions of the chain (@#@ ⋉max = 1044 and 1086 nm, respectively). To make comparisons, anionic dyes with analogous structure of the polymethine chain, viz., 1,3-dimethylbarbituric and 1,3-diethylthiobarbituric acid derivatives, have been also synthesized. Quantum chemical analysis
of the electron structure of the dyes has been performed. Their solvatochromism in polar solvents depends weakly on electrophilicity
and nucleophilicity of the medium and is primarily determined by universal interactions. This is the reason that they, in
contrast to cationic dyes, retain a high selectivity of absorption (sharp absorption bands) and universal contour of electronic
bands in strong polar solvents even with the long polymethine chain. Special solvatochromic effects of the anionic dyes in
weakly polar media have been revealed and interpreted. The role of a counterion in these effects has been analyzed. 相似文献
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Improvements in the energy density of electric double-layer capacitors (EDLCs) can in particular be gained by enhancing their capacitance. Recent findings suggest that the specific capacitance can be increased by matching the sizes of pores and desolvated ions. However, on such matching, we evidenced that charge storage saturation can occur in organic electrolyte before reaching the maximum voltage, e.g. 2.7 V, due to the insufficiently developed porosity. The experimental charge is larger than the calculated on account of the size of rigid cations, because of the intercalation-like behaviour and/or distortion of ions. The experimental and calculated values are less coincident for the higher sweep rates, which reveals that the optimal average pore size should depend on the current load, tending to shift to higher values in the normal usage conditions of supercapacitors. 相似文献
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I. V. Kurdyukova N. A. Derevyanko A. A. Ishchenko D. D. Mysyk 《Russian Journal of General Chemistry》2014,84(9):1722-1731
Di-, tetra-, and hexamethine merocyanines containing heterocyclic fragments with different electron-donor abilities have been synthesized on the basis of bis(2,2,3,3,4,4,5,5-octafluoropentyl)-4,5-dinitro-9H-fluorene-2,7-disulfonate. Their electronic absorption spectra in solvents with different polarities have been studied, and their electronic structure and electronic transitions have been analyzed by DFT and TDDFT quantum chemical calculations using B3LYP functional and 6-31G(d,p) basis set. The electronic structure of the synthesized merocyanines changes from neutral polyene to polymethine and dipolar polyene, depending on the electron-donor ability of the heterocyclic fragment, length of the polymethine chain, and solvent polarity. Therefore, these merocyanines display positive, negative, and reverse solvatochromism. 相似文献