Experimental and theoretical study of the pyrolysis of trichlorosilane

Pyrolysis of trichlorosilane (TCS) and copyrolysis of TCS with 1,3-butadiene were studied. The enthalpies and activation energies for the reactions of the products of TCS pyrolysis were found by quantum-chemical calculations. A direct study of the pyrolysis of TCS by mass spectrometry was carried out. Based on the thermochemical parameters found by quantum-chemical calculations and on the results of GLC and mass spectrometry concerning the composition of the pyrolysis products, it was concluded that the pyrolysis of TCS follows a scheme that includes formation of radicals and silylenes. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1659–1662, September, 1997.     

Condensed heterocycles. 39. Quantum-chemical calculations of the reactivities of some condensed sulfur and selenium heterocycles

A number of isomeric thienothiophenes, selenophenothiophenes, and selenopheno-selenophenes, as well as their C-protonated forms ( complexes), were calculated by the self-consistent-field (SCF) MO LCAO method with the CNDO/2 approximation and the spd basis. Their reactivities in electrophilic substitution reactions were investigated theoretically by means of the localization energy approach. The results were compared with the available experimental data. The dependence of the specificity of electrophilic attack on the size of the attacking reagent was investigated for compounds with various heteroatoms. It is shown that the reactivity of the position relative to the selenium atom should increase as the size of the attacking reagent increases.See [1] for communication 38.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 199–202, February, 1980.     

The relationship between the density of the unpaired electron and reactivity of free radicals

Theoretical and Experimental Chemistry -     

Unstable complexes of sandwich compounds with small molecules. Communication 4. Quantum-chemical investigation of acetylene and methane coordinated with cyclopentadienyl π-complexes of the transition metals

Conclusions Based on INDO-type calculations in the Clack parametrization, it has been demonstrated that it is possible for metallocenes of the 3d-series to form complexes with acetylene and methane. For complexes of Cp₂M, M=Ti, V, Mn, and Ni with methane molecules, structures of the type Cp₂M(H)(CH₃) are probable.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 594–597, March, 1988.     

Electronic structures,physical properties,and reactivities of five-membered aromatic heterocycles (review)

The possibilities of modern quantum-chemical methods for the investigation of the electronic structures and reactivities of five-membered heteroaromatic compounds are examined.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 3–22, January, 1977.The authors thank Professor Ya. L. Gol'dfarb for the introduction he wrote for this review and for a number of valuable comments, as well as Doctor of Chemical Sciences L. I. Belen'kii for his useful discussion.