排序方式: 共有52条查询结果,搜索用时 15 毫秒
1.
Gostev F. E. Petrukhin A. N. Titov A. A. Shienok A. I. Marevtsev V. S. Sarkisov O. M. 《Russian Chemical Bulletin》2003,52(3):557-561
Intramolecular processes in electronic-excited states of 2,4,5-triarylimidazole molecules were studied by femtosecond laser spectroscopy. Experiments were carried out with two types of compounds, namely, those experiencing intramolecular proton transfer and two model compounds in which it is impossible. Schemes of the processes studied were proposed and the characteristic rate constants were determined. The excited-state intramolecular proton transfer (ESIPT) in the molecules with planar structure of the reaction center is a very fast process (100 fs). If the reaction center has a nonplanar structure and, hence, the intramolecular hydrogen bond is weakened, the ESIPT time is determined by the time of conformational rearrangement of the molecule. 相似文献
2.
A. G. Ovcharenko A. V. Lyubimov V. Yu. Nedoshivin V. S. Marevtsev M. I. Cherkashin 《Russian Chemical Bulletin》1990,39(3):471-474
The photochromic properties of nitro-substituted spironaphthooxazines in polymer matrices of different polarity were investigated and the quantum yields of photocoloration and parameters of the dark decolorization reaction, which is a disperse process, were determined. The features of the behavior of the nitro-substituted spironaphthooxazines are determined by the more efficient reaction of the photoinduced form with the medium, which is the consequence of stabilization of the bipolar structure of the molecule of the colored form.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 543—547, March, 1990. 相似文献
3.
V. G. Luchina V. S. Marevtsev I. Yu. Sychev T. Ya. Vlasenko Yu. D. Khamchukov M. I. Cherkashin 《Russian Chemical Bulletin》1992,41(1):72-76
The photochromic properties of 1,3,3-trimethylspiro[indolin-2,3-3H-anthraceno[2,1-b][1,4]-oxazine] (SAO) in solutions of different polarity [n-BuOH and petroleum ether (PETh)] were studied. It was established that the quantum yield of the photocoloration AB and the energy of activation of the thermal decolorization Ea in the PETh depend on the temperature; this is not the case in n-BuOH. The luminescence properties of SAO were investigated. It was found that the spectrum of the excitation of the luminescence in PETh depends on the temperature. These features, as well as the slower thermal decolorization of the colored form of SAO in PETh by comparison with the solutions in n-BuOH, are explained by the presence of dimers of the SAO molecules in nonpolar media in the temperature range investigated (77–300 K), whereas the SAO molecules already occur in the monomeric state at 150 K in the polar n-BuOH.N. N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 117977 Moscow. Branch of the Institute of the Physics of Solids and Semiconductors, Academy of Sciences of Belarus, 211177 Vitebsk. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 93–98, January, 1992. 相似文献
4.
V. G. Luchina I. Yu. Sychev V. S. Marevtsev T. Ya. Vlasenko Yu. D. Khamchukov M. I. Cherkashin 《Russian Chemical Bulletin》1992,41(1):77-82
The influence of temperature and concentration on the spectral polarization properties of the luminescence and absorption of molecules of the original form of photochromic spiroanthrooxazine (SAO) in petroleum ether and polyethylene was investigated. It was shown that the long-wave part of the absorption spectra of the molecules is formed by at least two -*-type electronic transitions, the oscillators of which are mutually orthogonal. It is suggested that the SAO molecules form dimers in nonpolar media through dipole-dipole interaction, and at high concentrations they also form higher associates. Dimers stable in the ground state dissociate when excited to the second electronic transition with a rate constant of 1012–1013 s–1.N. N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 117977 Moscow. Department of the Institute of Solid-State Physics and Semiconductors, Academy of Sciences of Belarus, 211177 Vitebsk. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 99–106, January, 1992. 相似文献
5.
Photochromism of 1′,3′,3′-trimethyl-6-piperidinospiro [indoline-2′,3-3H-naphth [2,1-b][1,4]-oxazine]
The effect of the piperidine substituent on the spectral and photochromic properties of spiro(indoline-naphthoxazines) (SINO) in different solvents is studied. The introduction of this substituent into the naphthoxazine fragment of SINO results in the appearance of fluorescence of the initial formA of SINO at low temperatures. This fluorescence gradually disappears as the temperature increases. The temperature and concentration dependences of the spectral parameters of photoinduced formB of SINO make it possible to assume thatB molecules aggregate in non-polar solvents. In all solvents studied, form B, unlike the photoinduced form of the non-substituted spiro naphthoxazine, is stabilized as a bipolar ion with a positive charge on the nitrogen atom of the piperidine substituent. The increase in the rate of thermal decolorization as the medium polarity increases is explained.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 684–688, April, 1995.The authors are grateful to the Belarus' Foundation for Basic Research for financial support of this work. 相似文献
6.
7.
Yu. D. Khamchukov V. G. Luchina A. T. Gradyushko V. S. Marevtsev A. V. Lyubimov M. I. Cherkashin 《Journal of Applied Spectroscopy》1990,52(5):513-517
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 52, No. 5, pp. 768–773, May, 1990. 相似文献
8.
V. Yu. Nedoshivin N. L. Zaichenko N. N. Glagolev Y. S. Marevtsev 《Russian Chemical Bulletin》1996,45(5):1182-1184
Hydrogenatjon of 8-nitrospironaphthoxazine (1) resulted in the corresponding amine (2). Acylation of compound 2 yielded the N-methacryloyl derivative (3). Radical polymerization of the latter resulted in its copolymers with styrene, which possess photochromic properties.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1243–1245, May, 1996. 相似文献
9.
Conclusions Thermally induced formation of colored complexes which result in the amorphous and crystalline states of solid compounds takes place in a concentrated solution of 6-nitrospiropyrans in a polar solvent.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 1984–1986, September, 1984. 相似文献
10.