We present a combined theoretical and experimental investigation on the single photoionization and dissociative ionization of gas-phase methyl ketene (MKE) and its neutral dimer (MKE2).

Propynal (HCCCHO) is a compound of considerable astrochemical interest and observed in several interstellar objects.

Acetamide, a small organic compound containing a peptide bond, was observed in the interstellar medium, but reaction pathways leading to the formation of this prebiotic molecule remain uncertain. We investigated the possible formation of a peptide-like bond from the reaction between acetic acid (CH 3 -COOH) and methylamine (CH 3 -NH 2 ) that were identified in the interstellar medium. From an experimental point of view, a quadrupole/ octopole/quadrupole mass spectrometer was used in combination with synchrotron radiation as a tunable source of VUV photons for monitoring the reactivity of selected ions. Acetic acid was photoionized, and the reactivity of CH 3 COOH +• as well as COOH + (produced from either acetic acid or formic acid) ions with neutral CH 3 NH 2 was further studied. With no surprise, charge transfer, proton transfer, and concomitant dissociation processes were found to largely dominate the reactivity. However, a C(O)−N bond formation process between the two reactants was also evidenced, with a weak cross section reaction. From a theoretical point of view, results concerning reactivity and barrier heights were obtained using density functional theory, with the LC-ωPBE range-separated functional in combination with the 6-311++G(d,p) Pople basis set and are in perfect agreement with the experimental data.