Very low pressure pyrolysis of phenyl acetate

The kinetics of the unimolecular decomposition of phenyl acetate into phenol and ketene, reaction (1): has been studied under very low-pressure conditions between 950 and 1120 K. In this range alternative processes such as the Fries rearrangement to o-hydroxyacetophenone or bond fission into phenoxyl and acetyl radicals are not observed. Based on present and previous evidence a novel four-center transition state is proposed for reaction (1) which corresponds to the high-pressure Arrhenius expression log (k₁, s^?1) = 12.8 – 56.2/θ, θ = 4.575 × 10^?3T kcal/mol.