Thermal ion-molecule reactions in oxygen-containing molecules. Condensation-elimination reactions involving CH 3+ and C 2H 4O + in acetaldehyde and ethylene oxide

Abstract

The condensation-elimination reactions involving CH 3 + and C 2H 4O + in acetaldehyde and ethylene oxide have been studied using a time-of-flight mass spectrometer. The CH 3 + ions react with acetaldehyde and ethylene oxide to form C 2H 3 +, C 2H 4 +, C 2H 5 + and CH 3O +. Further studies in the reactions of CH 3 + were made in methane-acetaldehyde (or ethylene oxide) mixtures, and the formation mechanism of C 2H 5 + and CH 3O + was elucidated. The C 2H 4O + ions react with acetaldehyde and ethylene oxide to form C 3H 5O +, C 3H 6O +, and C 3H 7O +. Mechanistic studies in the ionic reactions involving the isomeric ions (CH 3CHO + and CH 2CH 2O +) was also made in acetaldehyde-d 4-ethylene oxide mixtures. From the distribution of isotopic product ions, the structures of the product ions and the condensation-elimination reaction mechanism were examined. In addition, the rate constants for the product ions were obtained.