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881.
Some novel physical ideas and mathematical techniques are described, useful in the development of effective Hamiltonian methods for studying molecular environmental effects. 相似文献
882.
A. A. Korlyukov K. A. Lyssenko M. Yu. Antipin A. G. Shipov O. A. Zamyshlyaeva E. P. Kramarova Vad. V. Negrebetsky S. A. Pogozhikh Yu. E. Ovchinnikov Yu. I. Baukov 《Russian Chemical Bulletin》2004,53(9):1924-1931
The reaction of 4-(2-hydroxybenzoyl)-2,2,6,6-tetramethyl-2,6-disilamorpholine with BF3Et2O afforded (O-B)-chelate 4-[2-(difluoroboroxy)benzoyl]-2,2,6,6-tetramethyl-2,6-disilamorpholine. Treatment of the latter with BF3Et2O or SOCl2 gave rise to products of the disilamorpholine ring opening, viz., (O-B) chelate 2-(difluoroboroxy)-N,N-bis(dimethylfluorosilylmethyl)benzamide or 2-(difluoroboroxy)-N, N-bis(dimethylchlorosilylmethyl)benzamide, respectively. The structures of the compounds synthesized were confirmed by X-ray diffraction analysis and 1H, 13C, and 29Si NMR spectroscopy. High-precision X-ray diffraction study and quantum-chemical calculations demonstrated that the coordination OSi bond is absent in the two last-mentioned compounds.Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1846–1853, September, 2004. 相似文献
883.
The reaction of carboxymethyl polysaccharides and their ethyl esters with amines was studied with the aim to determine how the structure of the polymeric acylating agent affects the composition of the reaction products. 相似文献
884.
885.
V. D. Orlov N. V. Getmanskii O. V. Shishkin E. E. Lakin V. P. Kuznetsov 《Chemistry of Heterocyclic Compounds》1993,29(3):301-306
By the reaction of 2-nitrochalcone with hydrazine hydrate, 5-(2-nitrophenyl)-3-phenyl-1H-2-pyrazoline (I) and the hydrazone of 3-(5-(2-nitrophenyl)-3-phenyl-2-pyrazolin-1-yl)-3-(2-nitrophenyl)propiophenol (II) have been prepared. The acylation of both compounds I and II leads to N-acyl derivatives of the first. The acylating ability of formamide and N,N-dimethylformamide was observed in reactions with pyrazoline I. An x-ray structural study was carried out on compound II.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 360–366, March, 1993. 相似文献
886.
I. V. Moiseeva P. M. Lukin O. E. Nasakin V. N. Romanov V. A. Tafeenko A. Kh. Bulai P. A. Sharbatyan 《Chemistry of Heterocyclic Compounds》1992,28(2):237-237
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, p. 282, February, 1992. 相似文献
887.
888.
F. M. Stoyanovich E. P. Zakharov O. V. Lysenko V. N. Yarovenko M. M. Krayushkin 《Russian Chemical Bulletin》1991,40(1):225-227
Preparative syntheses have been developed for 2-amino-5-cyano-1,3,4-oxadiazole from the semicarbazone of methyl glyoxylate and some of its transformations were studied. This product is an important intermediate in the preparation of its derivatives.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1. 243–246, January, 1991. 相似文献
889.
M. O. Lozinskii Yu. A. Fialkov V. S. Khomenko T. A. Pavich 《Theoretical and Experimental Chemistry》1990,26(2):228-231
A series of new adducts of fluorinated REE -diketonates with triphenylphosphine oxide was synthesized. The paths of their fragmentation under electron impact were investigated. It was shown that in contrast to the complex with 1,1,1,2,2,3,3-heptafluoro-7,7-dimethyloctane-4,6-dione, the complexes of europium with 1-trifluoromethoxy-1,1-difluoro-5,5-dimethylhexane-2,4-dione and 1, 1,1-trifluoro-5,5-dimethylhexane-2,4-dione form dimeric associates in the gaseous phase. The reasons for this difference in the behavior of the complexes and the possible structure of one of the dimers are discussed.Translated from Teoreticheskaya i Eksperimental'naya Khimiya, Vol. 26, No. 2, March–April, 1990. 相似文献
890.
H. O. Denschlag 《Journal of Radioanalytical and Nuclear Chemistry》1990,142(1):5-11
A historical account on the details of the discovery of nuclear fission in 1939 is given.After an address presented at the INS Conference on Nuclear Science and Technology in India-Past, Present and Future BARC, Bombay, 18th January 1989. 相似文献