Synthesis,molecular and crystal structures,and characteristic features of electronic structures of salicylamide-based B,Si-containing chelates

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.     

Reactions of Carboxymethyl Polysaccharides and Their Ethyl Esters with Amines

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.     

Pyrazolines — Derivatives of 2-nitrochalcone

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.     

Synthesis of 5-amino-3a,4-dicyano-2,3,3a,6a-tetrahydrofuro[2,3-b]pyrroles

Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, p. 282, February, 1992.     

Synthesis of 2-amino-5-cyano-1,3,4-oxadiazole and some of its derivatives

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.     

Mass spectrometric study of mixed fluorinated rare earth element β-diketonates with triphenylphosphine oxide

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.     

The discovery of nuclear fission 50 years ago a few remarks

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.     

Molecular and crystal structure of N,N′-di-(p-tosyl)-2,8-dimethoxyphengomazine-6,12-dione

Branch of the Institute of Chemical Physics, Academy of Sciences of the USSR. Translated from Zhurnal Strukturnoi Khimii, Vol. 29, No. 5, pp. 109–115, September–October, 1988.