Photodissociation kinetics of the isobutanal radical cation: a combined experimental and theoretical study

Abstract

The competitive photodissociation kinetics of the isobutanal radical cation ((CH₃)₂CHCHO⁺˙, 1) were investigated using experimental and theoretical methods. The photodissociation was followed by the 2 + 1 REMPI process in the gas phase. The reaction pathways for the main product ions with m/z 43 and 29 were determined by calculating the potential energy surface of the dissociation with the G4 method. Through a kinetic analysis using RRKM calculations, we proposed that the main photodissociation pathways were 1 → (CH₃)₂CH⁺ + CHO˙, 1 → (CH₃)₂CH⁺ + H˙ + CO, and 1 → CH₃CH₂COCH₃⁺˙ → CH₃CH₂⁺ + CH₃˙ + CO.