Dissociation of methyl formate (HCOOCH₃) molecules upon low-energy electron attachment

Abstract

Context. The methyl formate molecule (HCOOCH 3 ) is considered to be a key molecule in astrochemistry. The abundance of this molecule in space depends on the stability upon irradiation with particles like low-energy electrons. Aims. We have investigated the decomposition of the molecule upon electron capture in the electron energy range from about 0 eV up to 15 eV. All experimentally obtained fragmentation channels of the molecular anion were investigated by quantum chemical calculations. Methods. A high resolution electron monochromator coupled with quadrupole mass spectrometer was used for the present laboratory experiment. Quantum chemical calculations of the electron affinities of the generated fragments, the thermodynamic thresholds and the activation barriers for the associated reaction channels were carried out to complement the experimental studies. Results. Electron attachment is shown to be a purely dissociative process for this molecule and proceeds within two electron energy regions of about 1 eV to 4 eV and from 5 eV to 14 eV. In our experiment five anionic fragments with m/z (and possible stoichiometric structure) 59 (C 2 H 3 O Conclusions. The low-energy electron induced dissociation of methyl formate differs from its isomers acetic acid and glycolaldehyde, which leads to possible chemical selectivity in the chemical evolution.

Fast Heavy-Ion-Induced Anion–Molecule Reactions on the Methanol Droplet Surface

“…Production of methyl formate (CH 3 OCHO) was reported in a study of MeV-energy heavy ion irradiation on methanol ice . The DEA to methyl formate is likely to produce more CHO – than C 2 H 3 O 2 – . In the present experiments, the CHO – yield was much less than that of C 2 H 3 O 2 – .…”

“…4 The DEA to methyl formate is likely to produce more CHO − than C 2 H 3 O 2 − . 44 In the present experiments, the CHO − yield was much less than that of . 45 In the present experiments, DEA to acetic acid can be excluded because of the absence of the peak at m/z = 46 (Figure 4).…”

“…4 The DEA to methyl formate is likely to produce more CHO − than C 2 H 3 O 2 − . 44 In the present experiments, the CHO − yield was much less than that of C 2 H 3 O 2 − . Thus, DEA to methyl formate negligibly contributed to the present experiments.…”

Negative ion formation and fragmentation upon dissociative electron attachment to the nicotinamide molecule

“…More detailed description of the DEA process can be found, for instance, in the work by Feketeová et al 41 In order to check the anion species formed by electron attachment to NA molecules, multiple mass scans were performed at several incident electron energies in steps of 0.5 eV. For the detected anions, more detailed studies regarding the energetics of the electron capture process, leading to the formation of the measured anions, were performed.…”

Predicting dipole orientations in spontelectric methyl formate

“…Experiments are done in the gas phase and theory is considering here the single molecule. Feketeova et al [23] have studied dissociation of MF molecules in an electron attachment spectrometer and have supported the dissociation study by ab initio calculations. Thakur et al [24] have studied i.a.…”