Thermal ion–molecule reactions in oxygen-containing molecules. Formation of long-lived intermediate ions in acetyl chloride

Abstract

The thermal ion–molecule reactions in acetyl chloride have been studied. The dissociation reaction of long-lived intermediate ions (CH3COClH+*) leading to the formation of CH3CO+ was observed. The formation of CH3COClH+ was confirmed from the detection of the metastable ions, and CH3COClH+* results from the reaction of CH3CO+ with acetyl chloride. CH3CO+ reacts with acetyl chloride to form CH3COClH+. In n-propyl acetate–acetyl chloride mixtures, the ion–molecule reactions involving CH3CO+ and CH3COOH+2 have been investigated to clarify the effect of reactant ions on the formation of CH3COClH+*. The reaction channel of CH3CO+ from n-propyl acetate with acetyl chloride to form CH3COClH+ is more probable than that of CH3CO+ from acetyl chloride. CH3CO+ from acetyl chloride led preferentially to the formation of CH3COClH+* in comparison with reactions of CH3CO+ from n-propyl acetate. The measurement of the translational energies of both CH3CO+ ions allows a clear elucidation of the detailed mechanism of dissociation of CH3COClH+* ions formed in the mixtures.