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91.
92.
The vibration spectrum of perfect carbon nanotubes is studied using a two-parametric potential which includes pairwise and three-particle interatomic interactions. This potential was proposed by Keating and allows one to take into account the elasticity of pairwise interatomic bonds and the elasticity associated with a change in the angle between directional interatomic bonds in covalent crystals. Using the Keating potential, the vibration spectrum of a graphite monolayer is calculated and fitted to the vibration spectrum of crystalline graphite, thereby determining the parameters of the potential. With these parameters, the phonon spectra of perfect monolayer graphite nanotubes are calculated. A continuum model, in which a monolayer nanotube is represented as an elastic cylindrical shell of a finite thickness, is also discussed. Within this model, the vibration spectrum of a nanotube is calculated numerically in the long-wavelength limit as a function of the radius and thickness of the nanotube. 相似文献
93.
O. V. Bykhovskaya I. M. Aladzheva D. I. Lobanov P. V. Petrovskii K. A. Lyssenko I. V. Fedyanin T. A. Mastryukova 《Russian Chemical Bulletin》2005,54(11):2642-2647
2-Oxo-1,2-azaphospholanes and 1,2-azaphospholanium salts containing an amino acid fragment were synthesized by intramolecular
P-alkylation of N-3-chloropropyl-substituted tricoordinate phosphorus amides. Hydrolysis of 2-oxo-1,2-azaphospholanes at the P-N bond gives
rise to γ-aminopropylphosphonic acid derivatives.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2557–2562, November, 2005. 相似文献
94.
The reaction of Ca(BH4)2 · 1.5Dg with decaborane-14 in diglyme at 85°C yields Ca(B11H14)2 · 4Dg. The duration of the reaction is 20 h. The molar ratio of Ca(BH4)2 · 1.5Dg: B10H14 is 1: 3.5. The yield is 84.7%. The synthesized calcium tetradecahydroundecaborate Ca(B11H14)2 · 4Dg is a stable compound soluble in water and a number of organic solvents. The study of the compound was carried out using
elemental analysis and IR and NMR 11B {1H} spectroscopy. Calcium undecaborate can be used for synthesizing other salts with boron hydride nido-borates. 相似文献
95.
I. I. Ponomarev M. Yu. Zharinova Z. S. Klemenkova P. V. Petrovskii Z. A. Starikova 《Russian Chemical Bulletin》2011,60(3):512-520
The reaction of 1,8-naphthalic anhydride with 2-aminophenol afforded N-(2-hydroxyphenyl)-1,8-naphthalimide, which was then derivatized at the hydroxy group. 相似文献
96.
Khlebnikov AF Novikov MS Golovkina MV Petrovskii PP Konev AS Yufit DS Stoeckli-Evans H 《Organic & biomolecular chemistry》2011,9(10):3886-3895
An effective approach to azepino-fused heterocycles is described. trans-1-Aryl-7,11b-dihydro-1H-azirino[1,2-a]dibenzo[c,f]azepines were synthesised via a domino sequence: isomerization of gem-dichloroaziridine-intramolecular Friedel-Crafts acylation of the tethered benzene ring catalysed by SnCl(4) and subsequent hydride induced intramolecular cyclization. Cycloaddition of dibenzazepinium ylides, generated by heating these aziridines, to activated C[double bond]C, C[triple bond]C dipolarophiles and fullerene C(60), leads to derivatives of dibenzo[c,f]pyrrolo[1,2-a]azepine. The reaction proceeds with complete stereoselectivity via cycloaddition of only W-ylide, which due to the high barrier does not undergo E,Z-isomerization under the reaction conditions. It was found that 2,3,9,13b-tetrahydro-1H-dibenzo[c,f]pyrrolo[1,2-a]azepine systems can exist in conformations of two types depending on the substituents at the pyrrolidine carbons in β-position with respect to nitrogen. Details of cycloaddition reactions and the conformational behavior of cycloadducts were studied by DFT calculations at the B3LYP/6-31G(d) level. 相似文献
97.
L. I. Strunkina M. Kh. Minacheva P. V. Petrovskii Z. S. Klemenkova B. V. Lokshin V. V. Burlakov V. B. Shur 《Russian Chemical Bulletin》1997,46(4):820-823
The first acetylene complex of hafnium, Cp2Hf[Me3SiC=CHf(H)Cp2], was synthesized by the reaction of hafnocene dihydride Cp2HfH2 with bis(trimethylsilyl)acetylene in benzene. The reaction is accompanied by elimination of the Me3Si group from the molecule of the initial acetylene, as a result of which the acetylenide derivative of hafnium Cp2Hf(C=CSiMe3)(H) acts as an acetylene ligand in the complex. Under analogous conditions, the reaction of zirconocene dihydride Cp2ZrH2 with bis(trimethylsilyl)acetylene affords an analogous acetylene complex of zirconium Cp2Zr(M3SiC=CZr(H)Cp2]. Reactions of Cp2HfH2 with tolane and 3-hexyne proceed differently than the reaction with bis(trimethylsilyl)acetylene. Here the corresponding
hafnacyclopentadiene metallacycles are the final products.
For preliminary communication, see Ref. 3.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 853–856, April, 1997. 相似文献
98.
G. N. Molchanova T. M. Shcherbina P. V. Petrovskii E. E. Nifant'ev 《Russian Chemical Bulletin》2005,54(5):1245-1249
Methods for the synthesis of tetramethylbis(ω-phosphoryloxyalkyl)disiloxanes were developed. Thermal rearrangement of the
1,2-shift type of tetramethylbis(phosphoryloxymethyl)disiloxanes was studied. The 1,2-shift rearrangement of dimethyl(diphenoxyphosphoryloxymethyl)silyl
hydrogen sulfate was found.
Dedicated to Academician N. K. Kochetkov on the occasion of his 90th birthday.
__________
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1210–1214, May, 2005. 相似文献
99.
Yu. G. Gololobov O. A. Linchenko Yu. G. Trishin P. V. Petrovskii S. A. Starikova 《Russian Chemical Bulletin》2004,53(4):889-896
The reaction of C,N-diphenylnitrilimine with a P-zwitterion derived from Pri
3P and H2C=C(CN)CO2Et afforded the first representative of 2-pyrazolines containing the phosphonium group and products of the addition of nitrilimine to Pri
3P and H2C=C(CN)CO2Et. The reaction of the P-zwitterion with C-4-nitrophenyl-N-phenylnitrilimine gave rise to a condensation product of one Pri
3P molecule and two nitrilimine molecules. The three-dimensional structures of the compounds synthesized were established by X-ray diffraction analysis. 相似文献
100.