Ab initio and DFT calculations of benzaldoxime elimination kinetics in the gas phase

Abstract:

The mechanism for the gas-phase molecular elimination kinetics of benzaldoxime was examined at MP2/6-31G, MP2/6-31G(d,p), B3LYP/6-31G, B3LYP/6-31G(d,p), MPW1PW91/6-31G, and MPW1PW91/6-31G(d,p) levels of theory. The products of elimination of this oxime are benzonitrile and water. Calculated thermodynamic and kinetic parameters estimated from B3LYP/6-31G was found to be in better agreement with the experimental values. Transition state structure is best described as a four-membered cyclic structure with good approximation to planarity. NBO charges analysis revealed a little greater polarization of the benzylic Cδ - Hδ+ rather than N δ - OHδ-. Bond indexes and synchronicity parameters are in agreement with a concerted semi-polar type of mechanism with benzylic C - H bond breaking as determining step of the reaction. ©2008 Wiley Periodicals, Inc.

Año de publicación:

2008

Keywords:

• Bezaldoxime
• DFT calculations
• Gas phase elimination
• kinetics
• Ab initio

Fuente:

scopus

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