Behavior of Hydroxyl Radicals on Water Ice at Low Temperatures

Abstract

Because chemical reactions on/in cosmic ice dust grains covered by amorphous solid water (ASW) play important roles in generating a variety of molecules, many experimental and theoretical studies have focused on the chemical processes occurring on the ASW surface. In laboratory experiments, conventional spectroscopic and mass-spectrometric detection of stable products is generally employed to deduce reaction channels and mechanisms. However, despite their importance, the details of chemical reactions involving reactive species (i.e., free radicals) have not been clarified because of the absence of experimental methods for in situ detection of radicals. Because OH radicals can be easily produced in interstellar conditions by not only the photolysis and/or ion bombardments of H2O but also the reaction of H and O atoms, they are thought to be one of the most abundant radicals on ice dust. In this context, the development of a close monitoring method of OH radicals on the ASW surface may help to elucidate the chemical reactions occurring on the ASW surface.

25 pages, 9 figures; Accepted for publication in Acc. Chem. Res

References in corpus (4)

• Complex Chemistry in Star-Forming Regions: An Expanded Gas-Grain Warm-up Chemical Model
• Water Formation through a Quantum Tunneling Surface Reaction, OH + H2, at 10 K
• Subsurface chemistry of mantles of interstellar dust grains in dark molecular cores
• Interactions of Atomic and Molecular Hydrogen with a Diamond-like Carbon Surface: H2 Formation and Desorption

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• Diffusive vs. non-diffusive paths to interstellar hydrogen peroxide. A machine learning-based molecular dynamics study
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