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1.
Richard P. Kent IV 《Geometriae Dedicata》2004,106(1):145-159
We answer a question of J. Anderson's by producing infinitely many commensurability classes of fibered hyperbolic 3-manifolds whose fundamental groups contain subgroups that are locally free and not free. These manifolds are obtained by performing 0–surgery on a collection of knots with the same properties. 相似文献
2.
M. G. Voronkov L. I. Larina Yu. I. Bolgova O. M. Trofimova N. F. Chernov V. A. Pestunovich 《Chemistry of Heterocyclic Compounds》2006,42(12):1585-1591
The 1H, 13C, 15N, and 29Si NMR, IR, and UV spectra of N-(1-silatranylmethyl) and N-(trimethoxysilylmethyl) derivatives of nitrogen heterocycles have
been studied. The dependence and interrelation of the chemical shifts of 29Si and 15N nuclei of the silatranyl group in the spectra of N-(1-silatranylmethyl)-substituted nitrogen heterocycles are determined
by the nature of the heterocyclic system.
__________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1857–1865, December, 2006. 相似文献
3.
V. A. Lopyrev L. I. Larina L. Kh. Baumane E. F. Shibanova R. A. Gavar S. M. Ponomareva T. I. Vakul'skaya Ya. P. Stradyn' 《Chemistry of Heterocyclic Compounds》1984,20(9):1021-1026
The electrochemical reduction of 2-substituted 5(6)-benzimidazoles has been studied with the aid of classical polarography and cyclic voltammetry in acetonitrile. The influence of the substituents in position 2 on the magnitudes of the half-wave potentials of the first stage is exerted by induction and resonance mechanisms with approximately the same contributions, and that on the magnitudes of the half-wave potentials of the second stage predominantly by the resonance mechanism. The possibilities of taking the radical-stabilizing factor into account in the correlations are discussed. In order to study the 2-substituted 5(6)-nitrobenzimidazole series, their pK
a
values in acetonitrile have been determined by potentiometric titration.For communication 3, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1246–1251, September, 1984. 相似文献
4.
N. A. Keiko Yu. A. Chuvashev T. A. Kuznetsova L. G. Stepanova L. I. Larina L. V. Sherstyannikova M. G. Voronkov 《Russian Chemical Bulletin》1998,47(7):1379-1381
Cyanosilylation of α-butylthioacrolein with trimethylsilyl cyanide occurs as 1,2-addition. Concurrent rapid dimerization of
α-butylthioacrolein occurred both in the presence and in the absence of H2PtCl6·6H2O as a catalyst to give 2,5-dibutylthio-2,3-dihydro-4H-pyran-2-carbaldehyde, whose cyanosilylation afforded the corresponding cyanohydrin. The latter is prone to retrodiene degradation
upon heating.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1418–1420, July, 1998. 相似文献
5.
6.
7.
T. I. Vakul'skaya L. I. Larina O. B. Nefedova V. A. Lopyrev 《Chemistry of Heterocyclic Compounds》1982,18(4):400-404
The results of an EPR investigation are presented with polarographs of electrochemical excitation of nitropyrazoles in acetonitrile. It is shown that 3- and 4-nitropyrazoles are excited in two single-electron stages with formation of dianion radicals. Upon excitation, N-alkylnitropyrazoles form stable anion radicals. 1-Nitro- and 1,4-dinitropyrazoles are excited upon splitting off of the NO2 anion. Excitation potentials of the nitropyrazoles and hyperfine interaction constants for the corresponding ion radicals are given.See [1] for Communication 2.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 523–527, April, 1982. 相似文献
8.
N.V. Kosova V.F. AnufrienkoT.V. Larina A. RougierL. Aymard J.M. Tarascon 《Journal of solid state chemistry》2002,165(1):56-64
Mechanical activation (MA) combined with heat treatment at moderate temperatures was used to prepare disordered and highly dispersed LiCoO2 starting from the mixtures of various cobalt precursors (CoOOH, Co(OH)2, and Co) and LiOH. X-ray powder diffraction and IR spectroscopy were used to investigate the phase composition and the crystal structure of as-prepared samples, while the electronic state of cobalt ions was characterized by diffuse reflectance electron spectroscopy. MA of the LiOH+CoOOH mixture led to the formation of LT-LiCoO2 with a cubic spinel-related structure. Heat treatment at 600°C of the latter resulted in the formation of HT-LiCoO2 with a hexagonal layered structure similar to ceramic LiCoO2. However, as-prepared HT-LiCoO2 is characterized by Co3+O6 octahedra less perfect than those of ceramic LiCoO2. All MA-LiCoO2 samples are exclusively described by localized d electrons. 相似文献
9.
N. A. Tyukavkina K. I. Lapteva V. A. Larina N. G. Devyatko 《Chemistry of Natural Compounds》1968,3(5):252-254
Summary The quantitative determination of quercetin and dihydroquercetin in the total flavonoids ofLatrix dahurica has been effected by the use of thin-layer chromatography on Kapron for separating the mixture with subsequent elution of the spots and colorimetry of the eluates obtained. The methanol-dimethylformamide (1:1) system was used as the eluate. It has been found that the flavonoids of the heartwood ofLatrix dahurica contain a predominating amount, 69% of dihydroquercetin, the amount of quercetin being 11%.Khimiya Prirodnykh Soedinenii, Vol. 3, No. 5, pp. 298–301, 1967 相似文献
10.
M. G. Voronkov O. M. Trofimova Yu. I. Bolgova L. V. Klyba L. I. Larina A. I. Albanov V. A. Pestunovich N. F. Chernov K. B. Petrushenko 《Chemistry of Heterocyclic Compounds》2003,39(12):1639-1644
We have synthesized 1- and 2-(trimethylsilylmethyl)- and 1- and 2-(trimethoxysilylmethyl)benzotriazoles by reaction of 1,2,3-benzotriazolylsodium with trimethyl- or trimethoxy(chloromethyl)silane. We obtained 1- and 2-(silatranylmethyl)benzotriazoles by transesterification of the latter with triethanolamine. 相似文献