Skip to Main content Skip to Navigation
Journal articles

Photoionization and dissociative photoionization of propynal in the gas phase: theory and experiment

Abstract : Propynal (HCCCHO) is a complex organic compound (COM) of astrochemical and astrobiological interest. We present a combined theoretical and experimental investigation on the single photon ionization of gas-phase propynal, in the 10 to 15.75 eV energy range. Fragmentation pathways of the resulting cation were investigated both theoretically and experimentally. The adiabatic ionization energy (AIE) has been measured to be AIEexp = 10.715 ± 0.005 eV using tunable VUV synchrotron radiation coupled with a double imaging photoelectron photoion coincidence (i2PEPICO) spectrometer. In the energy range under study, three fragments formed by dissociative photoionization were identified experimentally: HC3O+, HCO+ and C2H2+, and their respective appearance energies (AE) were found to be AE = 11.26 ± 0.03, 13.4 ± 0.3 and 11.15 ± 0.03 eV, respectively. Using explicitly correlated coupled cluster calculations and after inclusion of the zero point vibrational energy, core–valence and scalar relativistic effects, the AIE is calculated to be AIEcalc = 10.717 eV, in excellent agreement with the experimental finding. The appearance energies of the fragments were calculated using a similar methodological approach. To further interpret the observed vibrational structure, anharmonic frequencies were calculated for the fundamental electronic state of the propynal cation. Moreover, MRCI calculations were carried out to understand the population of excited states of the cationic species. This combined experimental and theoretical study will help to understand the presence and chemical evolution of propynal in the external parts of interstellar clouds where it has been observed.
Document type :
Journal articles
Complete list of metadatas

Cited literature [50 references]  Display  Hide  Download
Contributor : Laurent Jonchère <>
Submitted on : Wednesday, April 10, 2019 - 4:28:48 PM
Last modification on : Wednesday, January 13, 2021 - 9:41:34 AM


Derbali_Photoionization and di...
Files produced by the author(s)



Imene Derbali, Helgi Rafn Hrodmarsson, Zied Gouid, Martin Schwell, Marie-Claire Gazeau, et al.. Photoionization and dissociative photoionization of propynal in the gas phase: theory and experiment. Physical Chemistry Chemical Physics, Royal Society of Chemistry, 2019, 21 (26), pp.14053-14062. ⟨10.1039/C8CP06751A⟩. ⟨hal-02095692⟩



Record views


Files downloads