72024-84-1Relevant academic research and scientific papers
Kinetics and mechanism of monomolecular heterolysis of commercial organohalogen compounds: XLIII. Solvent effect on activation parameters of dehydrochlorination of 3-chloro-3-methylbut-1-ene. Correlation analysis of solvation effects
Ponomarev,Zaliznyi,Dvorko
, p. 1204 - 1214 (2008/02/12)
The influence of temperature on the rate of dehydrochlorination of 3-chloro-3-methylbut-1-ene in 17 aprotic and 13 protic solvents, ν = k[C 5H9Cl], was studied by the verdazyl method. In aprotic solvents, the electrophilicity, ionizing power, and cohesion of solvents decrease ΔG ≠ by increasing ΔS ≠. The nucleophilicity and polarizability increase both ΔH ≠ and ΔS ≠ to equal extent and therefore do not affect ΔG ≠. In protic solvents, the solvent nucleophilicity increases ΔH ≠ to a greater extent than ΔS ≠, and the overall effect of the nucleophilic solvation is small and negative.
Kinetics and mechanism of unimolecular heterolysis of framework compounds: XX. Solvation and steric effects in heterolysis of 2-halo-2-alkyladamantanes in sulfolane and butanol
Dvorko,Vasil'kevich,Mikhal'chuk,Koshchii
, p. 188 - 191 (2007/10/03)
Hetrolysis rate of 2-halo-2-phenyladamantanes in BuOH is 1000 times higher than the heterolysis rate of 2-halo-2-methyladamantanes. The heterolysis rate in sulfolane does not depend on the substituent, but the phenyl group exhibits a negative steric effect.
Kinetics and Mechanism of Monomolecular Heterolysis of Commercial Organohalogen Compounds: XXXIV. Solvent Effect on the Heterolysis Rate of 1-Chloro-1-methylcyclohexane. Correlation Analysis of Solvation Effects in Heterolysis of 1-Chloro-1-methylcyclohexane and 1-Chloro-1-methylcyclopentane
Dvorko,Koshchii,Ponomareva
, p. 204 - 212 (2007/10/03)
The kinetics of heterolysis of 1-chloro-1-methylcyclohexane in 9 protic and 25 aprotic solvents at 25°C were studied by the verdazyl method. The kinetic equation is v = k[RCl] (El mechanism). The heterolysis rate of 1-chloro-1-methylcyclohexane in protic solvents is two orders of magnitude lower than that of 1-chloro-1-methylcyclopentane, whereas in low-polarity and nonpolar aprotic solvents the rates are close. A correlation analysis was made to reveal the solvation effects in heterolysis of both chlorides in a set of 9 protic and 25 aprotic solvents, and separately in protic and aprotic solvents.
Kinetics and mechanism of monomolecular heterolysis of commercial organohalogen compounds: XXXII. Solvent effects on activation parameters of heterolysis of 1-chloro-1-methylcyclopentane. Correlation analysis of solvation effects
Dvorko,Koshchii,Prokopets,Ponomareva
, p. 1882 - 1893 (2007/10/03)
Kinetics of heterolysis of 1-chloro-1-methylcyclopentane in MeOH, BuOH, cyclohexane, i-PrOH, t-BuOH, tert-C5H11OH, γ-butyrolactone, MeCN, PhCN, PhNO2, acetone, PhCOMe, cyclohexanone, and 1,2-dichloroethane at 25-50°C were studied by the verdazyl method. Correlation analysis of solvent effects on activation parameters of the reaction in 8 protic (additionally, AcOH and CF 3CH2OH) and 8 aprotic solvents together and separately in either group of solvents was performed. In all the solvents studied, two ΔH≠-ΔS≠ compensation effects were revealed.
KINETICS AND MECHANISM OF MONOMOLECULAR HETEROLYSIS OF FRAMEWORK COMPOUNDS. V. IONIZATION-FRAGMENTATION PROCESS IN DECOMPOSITION OF 1-ADAMANTYL CHLOROFORMATE
Ponomareva, E. A.,Yavorskaya, I. F.,Dvorko, G. V.
, p. 477 - 489 (2007/10/02)
The decomposition of 1-adamantyl chloroformate in acetonitrile, nitrobenzene, benzene, and isopropyl and tert-butyl alcohols in the presence of triphenylverdazyls as internal indicator was investigated preparatively and kinetically.In nitrobenzene small addition of water increase the reaction rate, and additions of tetraethylammonium halides reduce it.In isopropyl and tert-butyl alcohols and in nitrobenzene in the presence of tetraethylammonium halides the reaction rate depends on the nature of the substituent in the verdazyl.The reaction rate increases linearly with increase in the dielectric constant of the medium.It is assumed that an intimate ion pair is formed at the first stage of the reaction and undergoes fragmentation in the controlling stage to 1-adamantyl chloride or is converted into a solvent-separated ion pair.The latter reacts with the verdazyl or undergoes fragmentation to 1-adamantyl chloride.
