Effect of the nature of the solvent and the temperature on the frequency and intensity of the stretching vibration of the Ge-H bond in the IR spectra of 1-hydrogermatranes

Conclusions The Ge-H stretching vibration in the IR spectra of 1-hydrogermatranes varies under the influence of the solvent and the temperature as a result of the presence of the transannular Ge N bond. The change in the length of this bond with variation in the polarity of the solvent and the temperature of the solutions is smaller in germatranes than for the Si N bond in the isostructural silatranes.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1758–1761, August, 1985.     

3-H-pyrrolizin-3-ones

Previously unknown 1-alkylthio-3H-pyrrolizin-3-ones have been obtained by the condensation of pyrrole-2-dithiocarboxylates with CH acids containing ester groupings in the KOH-DMSO system. On treating the products with secondary amines they are readily converted into the corresponding 1-amino derivatives.Irkutsk Branch of the Russian Academy of Sciences, Irkutsk 664033. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 919–924, July, 1996. Original article submitted May 2, 1996.     

Mesomerically stabilized thioaldehydes. 3-Thioformylindole and its alkyl and phenyl derivatives

3-Thioformylindole and its previously unknown 2-methyl-, 2 -phenyl-, and 1-ethyl substituted derivatives have been synthesized by the thiolysis of the corresponding indolylmethylenimmonium perchlorates. The thioaldehydes containing no substitutdt at the nitrogen atom were isolated as crystalline solvates with DMSO and DMF. Monitoring of 3-thioformylindole formation was effected by polarography and spectrophotometry.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 493–496, April, 1996.     

Reactions of Heterocumulenes with Organometallic Reagents: X. Quantum-Chemical Study of the Reaction of Aliphatic Isothiocyanates with Lithiated Allenes. Intramolecular Rearrangements of 1,3,4-Azatrienes

Study of the potential energy surface for the reaction of isothiocyanates with -lithiated allenes showed that the formation of 1,3,4-azatriene occurs in one step through a four-center transition state. [1,5]-Sigmatropic rearrangements of 1,3,4-azatrienes and electrocyclizations of the resulting conjugated 1,3,5-azatriene systems lead to formation of dihydropyridine ring. Pyrrole structures are more likely to arise from protonation of 3-alkoxy-1,3,4-azatriene.     

New Polymeric Sorbents Based on N-(Vinyloxyethyl)dithiocarbamoylethylcarbonitrile

Homo- and copolymers based on N-(vinyloxyethyl)dithiocarbamoylethylcarbonitrile actively sorbing silver, gold, and mercury were prepared.     

Unusually Facile Pyrrolization of 2-Acetylcoumarone Oxime with Acetylene

The oxime of 2-acetylcoumarone reacts with acetylene under pressure in the system KOH-DMSO unusually readily forming 2-(2-pyrrolyl)coumarone and the corresponding O-vinyl oxime. Under more rigid conditions 2-(1-vinyl-2-pyrrolyl)coumarone is formed. The possibility of a two-stage transformation of 2-acylcoumarones into 2-pyrrolylcoumarones has therefore been demonstrated for the first time.__________Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 524–529, April, 2005.     

2,3,5,6-Tetra(vinylthio)difluorobenzene in Reactions with Difunctional Nucleophiles

Reaction of 2,3,5,6-tetra(vinylthio)difluorobenzene with ethylene glycol affords 1,4-bis[2,3,5,6-tetra(vinylthio)-4-fluorophenoxy-1-ethyloxy-]-2,3,5,6-tetra(vinylthio)benzene, with diethylene glycol arises 2,3,5,6-tetra(vinylthio)-4-(4-hydroxyethoxyethyloxy)-1-fluorobenzene, with 1,5-diaminopentane forms 1,5-bis[2,3,5,6-tetra(vinylthio)-4-fluoroanilino]pentane; in reactions with 2-aminoethanethiol and 2-mercaptoethanol occurs substitution of two fluorine atoms by RS groups.     

A study of photoelectron spectra in the framework of the semiempirical AM1 method

The characteristics of photoelectron (PE) spectra of 2-phenylpyrroles and biphenyls have been correlated with the UV spectroscopy data for their radical cations. The geometric and electronic structures of the compounds and radical cations have been calculated using the AM1 method. The absorption bands of the radical cations observed in the visible region of spectrum have been found to pertain to the quasi-Koopmans type,i.e., they are realized between the doubly and partially occupied -MO, but their energies differ strongly from those calculated on the basis of PE spectra. This is explained by the distinction between the spatial structure of a molecule and that of the respective radical cation. The second cause of the discrepancy between the data of the two spectral methods consists in orbital — interactions, which are most conspicuous in the case of 4(4)-halogen-substituted compounds.For Part 4 see ref. 1.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 869–874, May, 1993.     

Reactions of organylhalosilanes with 1,1,3,3-tetra- and hexamethyldisilazane

Organylchlorosilanes, and also SiCl₄, decompose 1,1,3,3-tetra- and hexamethyl-disilazanes with formation of hitherto unknown organylchlorosilazanes of general formulas R_4–nSiCl_n–1NHSiH(CH₃)₂ and R_4–nSiCl_n–1NHSi(CH₃)₃ (n=2–4) in yields of 54–98%. The IR and mass spectra of the prepared compounds were studied.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1159–1162, May, 1991.