Investigation of the reaction of 1,2,3-trimethyl-2-phenylbenzimidazoline with dehydrogenating reagents by EPR spectroscopy

The reaction of 1,2,3-trimethyl-2-phenylbenzimidazoline with a number of reagents that manifest dehydrogenating properties with respect to benziraidazolines was studied by EPR spectroscopy. These reagents convert 1,2,3-trimethyl-2-phenylbenzimidazoline to a relatively stable cation radical. The mechanism of the dehydrogenation of benzimidazolines is discussed taking into account the established facts.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 634–638, May, 1987.     

Catalytic mechanism of transition-metal compounds on Mg hydrogen sorption reaction

The catalytic mechanisms of transition-metal compounds during the hydrogen sorption reaction of magnesium-based hydrides were investigated through relevant experiments. Catalytic activity was found to be influenced by four distinct physico-thermodynamic properties of the transition-metal compound: a high number of structural defects, a low stability of the compound, which however has to be high enough to avoid complete reduction of the transition metal under operating conditions, a high valence state of the transition-metal ion within the compound, and a high affinity of the transition-metal ion to hydrogen. On the basis of these results, further optimization of the selection of catalysts for improving sorption properties of magnesium-based hydrides is possible. In addition, utilization of transition-metal compounds as catalysts for other hydrogen storage materials is considered.     

2,3-Diferrocenylcyclopropenone in the reaction with organomagnesium compounds

The reactions of 2,3-diferrocenylcyclopropenone with ethyl- and benzylmagnesium chlorides afford 3,3-diethyl- and 3,3-dibenzyl-1,2-diferrocenylcyclopropenes along with products of nucleophilic opening of the three-membered ring: ,-unsaturated and saturated ketones (cis-1,2-diferrocenylpent-1-en-3-one and cis-1,2-diferrocenyl-4-phenylbut-1-en-3-one, 4,5-diferrocenylheptan-3-one, and 3,4-diferrocenyl-1,5-diphenylpentan-2-one). The products of insertion of intermediate diferrocenyl(vinyl)carbene at one of the -bonds of the starting 2,3-diferrocenylcyclopropenone were also isolated: 4-(2-oxo-1-ferrocenylbutyl)- and 4-(2-oxo-3-phenyl-1-ferrocenylpropyl)-2,3,4-triferrocenylcyclobutenones. 3,3-Dibenzyl-1,2-diferrocenylcyclopropene and one of the diastereomers of 4,5-diferrocenylheptan-3-one were studied by X-ray diffraction analysis.     

Kinetics and mechanism of the reaction of nitro and halonitro compounds with potassium iodide and other reducing agents

Russian Chemical Bulletin -     

Small ring compounds—XXX : Homolytical aromatic substitution and hydrogen abstraction reaction with cyclopropyl radical

Homolytic aromatic substitution and hydrogen abstraction reactions with cyclopropyl radical were carried out to determine the reactivity and ionic character of cyclopropyl radical by examination of the orientation effect, partial rate factor and influence of substituents. By thermal decomposition of biscyclopropaneformyl peroxide in a series of substituted benzenes, the corresponding cyclopropylated benzene derivatives (the mixture of ortho, meta and para isomers) were obtained in moderate yield. In view of the orientation effect and the partial rate factor, the cyclopropyl radical seems to be fairly free from polar effect, and to resemble the phenyl radical more than the common alkyl radical although the cyclopropyl radical has a slightly higher reactivity than the phenyl radical. The relative reactivity of the 2-phenylcyclopropyl radical in the hydrogen abstraction reaction toward the benzylic position of ring-substituted toluenes gave good Hammett's correlation with the slope of + 0·20 suggesting little ionic character in the transition state. This result was in good agreement with the conclusion obtained from homolytic aromatic substitution reaction and with the chemical reactivity to be expected from the non-planar nearly sp²-hybridized conformation of the cyclopropyl radical.     

Aromatization of piperylene on aluminum oxide with dehydrogenating additives

Conclusions A study has been made of the conversion of piperylene (500°, nitrogen dilution) on aluminum oxide and on aluminum oxide containing 1% or 5% added K₂O. It has been shown that as the K₂O content is increased, the yield of C₁₀ arenes also increases, these arenes being formed by dehydrogenation of intermediate cyclodimers. When Cr₂O₃ is introduced into the alumina-potassia system, benzene and toluene predominate in the arenes; this is explained by participation of the cracked products in the aromatization.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 1961–1965, September. 1985.     

Mechanism of the reaction of quinobromide compounds with amines

Conclusions The mechanism of the reaction of quinobromide compounds with amines was studied by the kinetic method.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1212–1214, May, 1972.     

Study of the reaction of sulfur with organic compounds

A study is made of the action of sulfur on halogen derivatives of iso- and n-propylbenzene, with 1–3 chlorine or bromine atoms at various places in the side chain. Reaction of sulfur with α-chlorocumene, α, β-dichlorocumene, and α, β, β-trichlorocumene and mixtures of these, proves to be a new convenient method of preparing 4-phenyl-1,2-dithio-3-thione (40% yield). Sulfuration of mono-, di- and tri-exo-halogen derivatives of n-propylbenzene gives 5-phenyl-1,2-dithiol-3-thione in 11–18% yield. For Part XII see [1].     

Study of the reaction of sulfur with organic compounds

The reaction of sulfur with phenylchloromethanes of the type (C₆H₅)_mCCl_nH_{4-m -n}(m=1–3; n3) is investigated. New simple methods of synthesizing tetraphenylthiophene (from C₆H₅CH₂Cl) and thianaphtheno [3, 2-b] thianapthene or 2-phenyl-3-chlorothianaphthene (from C₆H₅CHCl₂) are developed. All the heterocyclic sulfur compounds synthesized are oxidized to the corresponding sulfones, Diphenylchloromethane when heated with sulfur smoothly gives a high yield of tetraphenylethylene, and triphenylchloromethane treated similarly gives triphenylmethane. C₆H₅CCl₃ and (C₆H₅)₂CCl₂ undergo practically no reaction with sulfur under the conditions investigated.For Part VII see [1].