University of Sussex
Browse

File(s) under permanent embargo

Adsorption and thermal processing of glycolaldehyde, methyl formate, and acetic acid on graphite at 20 K

journal contribution
posted on 2023-06-08, 21:26 authored by Daren J Burke, Fabrizio Puletti, Paul M Woods, Serena Viti, Ben Slater, Wendy BrownWendy Brown
We present the first detailed comparative study of the adsorption and thermal processing of the three astrophysically important C2O2H4 isomers glycolaldehyde, methyl formate, and acetic acid adsorbed on a graphitic grain analogue at 20 K. The ability of the individual molecule to form intermolecular hydrogen bonds is extremely important, dictating the growth modes of the ice on the surface and the measured desorption energies. Methyl formate forms only weak intermolecular bonds and hence wets the graphite surface, forming monolayer, bilayer, and multilayer ices, with the multilayer having a desorption energy of 35 kJ mol–1. In contrast, glycolaldehyde and acetic acid dewet the surface, forming clusters even at the very lowest coverages. The strength of the intermolecular hydrogen bonding for glycolaldehyde and acetic acid is reflected in their desorption energies (46.8 and 55 kJ mol–1, respectively), which are comparable to those measured for other hydrogen-bonded species such as water. Infrared spectra show that all three isomers undergo structural changes as a result of thermal processing. In the case of acetic acid and glycolaldehyde, this can be assigned to the formation of well-ordered, crystalline, structures where the molecules form chains of hydrogen-bonded moieties. The data reported here are of relevance to astrochemical studies of hot cores and star-forming regions and can be used to model desorption from interstellar ices during the warm up phase with particular importance for complex organic molecules.

History

Publication status

  • Published

Journal

The Journal of Physical Chemistry A

ISSN

1089-5639

Publisher

American Chemical Society

Issue

26

Volume

119

Page range

6837-6849

Department affiliated with

  • Chemistry Publications

Full text available

  • No

Peer reviewed?

  • Yes

Legacy Posted Date

2015-07-06

Usage metrics

    University of Sussex (Publications)

    Categories

    No categories selected

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC