A theoretical study of the kinetics and mechanism of the reaction between
methylene and acetone in the gas phase was performed using the density
functional theory method at UB3LYP levels of theory using a 6‑311G** basis
set. Equilibrium molecular geometries and harmonic vibrational frequencies
of the reactants, transition states, intermediates and product were calculated.
These calculations showed that the reaction proceeds through an asynchronous
concerted mechanism. The effect of fluorine substitution on the reaction
rate was investigated: the computed activation barrier exhibits a fairly high
sensitivity to the nature of substituents at the C7‑ and C8‑positions. Gibbs free
energies of activation for all structures were computed.
کلید واژگان :
methylene, acetone, density functional theory, dipolar cycloaddition, kinetics, thermodynamics, fluoroacetone
