Hydrogenation at low temperatures does not always lead to saturation: the case of HNCO

Abstract

Context. It is generally agreed that hydrogenation reactions dominate chemistry on grain surfaces in cold, dense molecular cores, saturating the molecules present in ice mantles. Aims. We present a study of the low temperature reactivity of solid phase isocyanic acid (HNCO) with hydrogen atoms, with the aim of elucidating its reaction network. Methods. Fourier transform infrared spectroscopy and mass spectrometry were employed to follow the evolution of pure HNCO ice during bombardment with H atoms. Both multilayer and monolayer regimes were investigated. Results. The hydrogenation of HNCO does not produce detectable amounts of formamide (NH2CHO) as the major product. Experiments using deuterium reveal that deuteration of solid HNCO occurs rapidly, probably via cyclic reaction paths regenerating HNCO. Chemical desorption during these reaction cycles leads to loss of HNCO from the surface. Conclusions. It is unlikely that significant quantities of NH2CHO form from HNCO. In dense regions, however, deuteration of HNCO will occur. HNCO and DNCO will be introduced into the gas phase, even at low temperatures, as a result of chemical desorption.

arXiv comment9 pages, 8 figures, accepted for publication in A&A

References in corpus (23)

• Complex Chemistry in Star-Forming Regions: An Expanded Gas-Grain Warm-up Chemical Model
• The c2d Spitzer Spectroscopic Survey of Ices Around Low-Mass Young Stellar Objects: I. H2O and the 5-8 um Bands
• Testing grain-surface chemistry in massive hot-core regions
• Laboratory evidence for efficient water formation in interstellar ices
• Experimental evidence for water formation on interstellar dust grains by hydrogen and oxygen atoms
• Formation of hydrogen peroxide and water from the reaction of cold hydrogen atoms with solid oxygen at 10K
• HI Narrow Line Absorption in Dark Clouds
• New Three Micron Spectra of Young Stellar Objects with H_2O Ice Bands
• A quantitative analysis of OCN- formation in interstellar ice analogs
• Desorption of CO and O2 interstellar ice analogs
• Origin of the 6.85 micron band near young stellar objects: The ammonium ion (NH4+) revisited
• A 3-5$\mu$m VLT spectroscopic survey of embedded young low mass stars II; OCN${}^{-}$
• Experimental evidence for water formation via ozone hydrogenation on dust grains at 10 K
• Chemistry in Infrared Dark Clouds
• Low Temperature Surface Formation of NH3 and HNCO: hydrogenation of nitrogen atoms in CO-rich interstellar ice analogues
• CO2 formation in quiescent clouds; an experimental study of the CO + OH pathway
• HNCO enhancement by shocks in the L1157 molecular outflow
• H-atom bombardment of CO2, HCOOH and CH3CHO containing ices
• An IR study of pure and ion irradiated frozen formamide
• The thermal reactivity of HCN and NH3 in interstellar ice analogues
• Laboratory evidence for the non-detection of excited nascent H2 in dark clouds
• The abundance of HNCO and its use as a diagnostic of environment
• Oxygen diffusion and reactivity at low temperature on bare amorphous olivine-type silicate

Cited by in corpus (44)

• Astrochemistry During the Formation of Stars
• Binding energies: new values and impact on the efficiency of chemical desorption
• Dust as interstellar catalyst I. Quantifying the chemical desorption process
• Gas phase formation of the prebiotic molecule formamide: insights from new quantum computations
• Formation of complex organic molecules in hot molecular cores through nondiffusive grain-surface and ice-mantle chemistry
• Ingredients for Solar-like Systems: protostar IRAS 16293-2422 B versus comet 67P/Churyumov-Gerasimenko
• The ALMA-PILS survey: First detections of deuterated formamide and deuterated isocyanic acid in the interstellar medium
• Seeds of Life in Space (SOLIS) III. Formamide in protostellar shocks: evidence for gas-phase formation
• Can Formamide Be Formed on Interstellar Ice? An Atomistic Perspective
• Chemical modelling of complex organic molecules with peptide-like bonds in star-forming regions
• Simultaneous Hydrogenation and UV-photolysis Experiments of NO in CO-rich Interstellar Ice Analogues; linking HNCO, OCN-, NH2CHO and NH2OH
• Interstellar formamide (NH${}_2$CHO), a key prebiotic precursor
• The formation of peptide-like molecules on interstellar dust grains
• SOLIS II. Carbon-chain growth in the Solar-type protocluster OMC2-FIR4
• Formation of the prebiotic molecule NH${}_2$CHO on astronomical amorphous solid water surfaces: accurate tunneling rate calculations
• An Approach to Estimate the Binding energy of Interstellar Species
• Complex organic molecules in low-mass protostars on Solar System scales -- II. Nitrogen-bearing species
• Identification of pre-biotic molecules containing Peptide-like bond in a hot molecular core, G10.47+0.03
• The family of amide molecules toward NGC 6334I
• Formation of NH2CHO and CH3CHO upon UV photoprocessing of interstellar ice analogs
• The GUAPOS project II. A comprehensive study of peptide-like bond molecules
• Thermal desorption of formamide and methylamine from graphite and amorphous water ice surfaces
• Deuteration of ammonia with D atoms on oxidized partly ASW covered graphite surface
• Chemical Variation among Protostellar Cores: Dependence on Prestellar Core Conditions
• The Difference in Abundances between N-bearing and O-bearing Species in High-Mass Star-Forming Regions
• Amides inventory towards the G+0.693-0.027 molecular cloud
• X-ray induced chemistry of water and related molecules in low-mass protostellar envelopes
• Digging into the Interior of Hot Cores with ALMA (DIHCA). III: The Chemical Link between NH${}_2$CHO, HNCO, and H${}_2$CO
• How chemistry influences cloud structure, star formation, and the IMF
• ALMA Survey of Orion Planck Galactic Cold Clumps (ALMASOP): I. Detection of New Hot Corinos with ACA
• Sulphur-rich cold gas around the hot core precursor G328.2551-0.5321. An APEX unbiased spectral survey of the 2 mm, 1.2 mm, and 0.8 mm atmospheric windows
• The hunt for formamide in interstellar ices: A toolkit of laboratory infrared spectra in astronomically relevant ice mixtures and comparisons to ISO, Spitzer, and JWST observations
• Stratified Distribution of Organic Molecules at the Planet-Formation Scale in the HH 212 Disk Atmosphere
• Diastereoselective Formation of trans-HC(O)SH Through Hydrogenation of OCS on Interstellar Dust Grains
• ALMA Observations of Molecular Complexity in the Large Magellanic Cloud: The N105 Star-Forming Region
• Formation of the simplest amide in molecular clouds: formamide (NH${}_2$CHO) and its derivatives in H${}_2$O-rich and CO-rich interstellar ice analogs upon VUV irradiation
• Modelling the abundance structure of isocyanic acid (HNCO) toward the low-mass solar type protostar IRAS 16293-2422
• Exploring the formation pathways of formamide near young O-type stars
• Enhanced formation of interstellar complex organic molecules on carbon monoxide ice
• The Molecular Composition of Shadowed Protosolar Disk Midplanes beyond the Water Snowline
• The physical and chemical structure of Sagittarius B2, VIII. Full molecular line survey of hot cores
• Pathways to Interstellar Amides via Carbamoyl (NH2CO) Isomers by Radical-Neutral Reactions on Ice Grain Mantles
• Sub-arcsecond Imaging of the Complex Organic Chemistry in Massive Star-forming Region G10.6-0.4
• Chemical complexity in protoplanetary disks in the era of ALMA and Rosetta