Calculation of mass spectra of some organic compounds undergoing two consecutive reactions from the molecular ions

The molecular ions of phenyl benzoate, methyl benzoate, t‐butylbenzene, phthalic anhydride, p‐dimethoxybenzene, o‐dimethoxybenzene and acetophenone each undergo two consecutive reactions ([M]+.→[A]+→[B]+). These unimolecular reactions are treated within the framework of the quasi‐equilibrium theory (QET); a simple modification of the original equation relating the rate constant (k) with the internal energy (E) was used to calculate mass spectra of the above compounds from 12 to 20 eV. Good agreement between calculated and observed spectra is obtained.