Dissociation-ionization and ionization-dissociation by multiphoton absorption of acetaldehyde at 266 and 355 nm. Dissociation pathways

Abstract

The experimental results from the interaction of a sample of acetaldehyde (CH$_3$ CHO) with laser radiation at intensities between 10$^9$ and 10$^{11}$~Wcm$^{-2}$ and wavelengths of 266 and 355 nm are reported. As a result of multiple photon absorption, cations from ionization-dissociation (I-D) or dissociation-ionization (D-I) processes, were detected using a reflectron time of flight mass spectrometer. The processes I-D is predominant at 355 nm and D-I is predominant at 266 nm. The formation of different ions is discussed. From analysis of the ratios between the ion currents [I(CH$_3$CO$^+$)+I(CO$^+$)]/[ I(CH$_3^+$)+I(HCO$^+$)], originated from the C-C bond or from the C-H bond breaking at different laser intensities, the predominant channels are determined.