A Theoretical Study of the Bifurcation Reaction II : Acetic Acid

Takahashi Osamu

Itoh Kuniharu

Saito Ko

Journal of Molecular Structure : THEOCHEM

The competing reactions in the thermal unimolecular decomposition of acetic acid were examined theoretically. Calculations of the transition state structures, the activation energies, and the intrinsic reaction coordinates (IRC) for the two competing reaction paths were performed by using the molecular orbital and the density functional theory. The potential barrier heights were mostly the same for the two competing reaction paths, which were consistent with previous studies. An examination of the mode coupling between the IRC and vibrational modes predicted no significant difference in the rates for the corresponding paths in agreement with experimental results. This is different from the case of formic acid which was reported in our previous paper of this series. The unimolecular reaction rate seems to be controlled by the number of effective vibrational modes which couple strongly with the IRC before the reactant arrives at the transition state.

Chemistry [ 430 ]

eng

Elsevier

Copyright (c) 2002 Elsevier Ltd.

[ISSN] 0166-1280

[DOI] 10.1016/S0166-1280(02)00030-1

[NCID] AA11533429

[DOI] http://dx.doi.org/10.1016/S0166-1280(02)00030-1 isVersionOf