Theoretical study of the elimination kinetics of several 2-substituted ethyl N,N-dimethylcarbamates in the gas phase, [(CH3)2NCOOCH2CH2Z, Z=CH2Cl, C≡CH, C≡N]

Mirna M. Heredia R., M. Loroño, Tania Córdova, Gabriel Chuchani

Resultado de la investigación: Contribución a una revistaArtículorevisión exhaustiva

3 Citas (Scopus)

Resumen

The theoretical studies of the gas-phase elimination of 2-substituted ethyl N,N-dimethylcarbamates (Z=CH2Cl, C≡CH, C≡N) were performed using ab initio MP2/6-31G and MP2/6-31G(d) levels of theory. The gas phase elimination reaction of these carbamates yields N,N-dimethylcarbamic acid and the corresponding substituted olefin in a rate-determining step. The intermediate N,N-dimethylcarbamic acid is unstable and rapidly decomposes through a four-membered cyclic transition state to dimethylamine and CO2 gas. The results of these calculations suggest a mechanism to be concerted, asynchronous, and a six-membered cyclic transition state structure. Plotting the relative theoretical rate coefficients against Taft's σ* values gave an approximate straight line (ρ*=0.4057, r=0.9894 at 360 °C). The correlation between experimental log krel vs. theoretical log krel. for these 2-substituted ethyl N,N-dimethylcarbamates gave an approximate straight line (r=0.9715 at 360 °C), suggesting the same type of mechanism.

Idioma originalInglés
Páginas (desde-hasta)131-137
Número de páginas7
PublicaciónJournal of Molecular Structure: THEOCHEM
Volumen770
N.º1-3
DOI
EstadoPublicada - 29 sep 2006

Huella

Profundice en los temas de investigación de 'Theoretical study of the elimination kinetics of several 2-substituted ethyl N,N-dimethylcarbamates in the gas phase, [(CH<sub>3</sub>)<sub>2</sub>NCOOCH<sub>2</sub>CH<sub>2</sub>Z, Z=CH<sub>2</sub>Cl, C≡CH, C≡N]'. En conjunto forman una huella única.

Citar esto