Soft X-Ray Irradiation of Methanol Ice: Formation of Products as a Function of Photon Energy

Chen, Yu-Jung; Ciaravella, A.; Muñoz, G. M.; Cecchi‐Pestellini, C.; Jiménez-Escobar, A.; Juang, K.-J.; Yih, T. S.

doi:10.1088/0004-637x/778/2/162

Cited by 55 publications

(63 citation statements)

References 24 publications

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“…Similar effects were obtained for a methanol ice by Chen et al (2013), with even larger differences in the product efficiencies between monochromatic (550 eV) and broadband fluxes. The situation is reminiscent of the case of extreme-ultraviolet photoprocessing, in which products saturate at very high irradiation rates (e.g., Baragiola et al 2013).…”

Section: Saturation Of Productssupporting

confidence: 75%

Chemical Evolution of a Co Ice Induced by Soft X-Rays

Ciaravella

Chen

Cecchi‐Pestellini

et al. 2016

ApJ

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We irradiated a pure carbon monoxide ice with soft X-rays of energies up to 1.2 keV. The experiments were performed using the spherical grating monochromator beamline at the National Synchrotron Radiation Research Center in Taiwan, exploiting both monochromatic (at 0.3 and 0.55 keV) and broader energy (0.25-1.2 keV) fluxes. The infrared spectra of the irradiated ices showed the formation of a number of products such as polycarbon monoand dioxides C n O m , and chains containing up to 10 carbon atoms. While a gentle increase in the energy absorbed by the ice sample is reflected by an increase in the column densities of newly born species, such correlation breaks down at very high fluxes. In this regime the production yield falls down sharply by about a factor of 100. The refractory residue obtained in the broad energy irradiation is a "compromise" between those obtained with proton irradiation of C 3 O 2 and CO ices in previous experiments. Finally, we discuss the possible implications for space chemistry

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Section: Saturation Of Productssupporting

confidence: 75%

Chemical Evolution of a Co Ice Induced by Soft X-Rays

Ciaravella

Chen

Cecchi‐Pestellini

et al. 2016

ApJ

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“…Therefore, it is essential to perform experiments exploiting pure methanol first to examine its role in the formation of these complex organic molecules. Previous simulation experiments using pure methanol ices (Chen et al 2013;Henderson & Gudipati 2015;Kaiser, et al 2015;Maity, et al 2015;Sullivan et al 2016) confirmed simple polyols and hydroxycarboxylic acids, such as ethylene glycol (HOCH2CH2OH), glycerol (HOCH2CH(OH)CH2OH), and glycolic acid (HOCH2COOH), during the temperature programmed desorption (TPD) phase of UV-light or energetic electrons processed ices.…”

Section: Introductionmentioning

confidence: 93%

“…Methanol has been found to be ubiquitous in interstellar ices such as Orion BN and AFGL989 at levels of up to 30% with respect to water (Gibb et al 2004). Since no laboratory simulation experiment can reproduce the chemical complexity and diverse radiation conditions of actual interstellar space simultaneously, we performed experiments using simple pure methanol ices first (Chen, et al 2013;Henderson & Gudipati 2015;Kaiser, et al 2015;Maity, et al 2015;Sullivan, et al 2016) before extending to more complex systems. Our experiments were conducted at doses of 168.9 ± 26.1 eV per methanol molecule representing typical life times of long-lived interstellar molecular clouds at ages of about 50 million years (Yeghikyan 2011;Jeffreson & Kruijssen 2018).…”

Section: Introductionmentioning

confidence: 99%

On the Production of Polyols and Hydroxycarboxylic Acids in Interstellar Analogous Ices of Methanol

Zhu

Turner

Meinert

2020

ApJ

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This laboratory work studied the production of complex organic molecules (COMs) in pure methanol (CH3OH) ices exposed to ionizing radiation in the form of energetic electrons. The chemical evolution of the ices during the electron irradiation at 10 K and subsequent warm-up phase to 300 K was monitored online and in situ via Fourier Transform Infrared (FTIR) spectrometry. Polyols and hydroxycarboxylic acids related absorptions were observed in the infrared spectra of the irradiated ices and residues at room temperature. The residues were analyzed via two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC-TOFMS). Four polyols and five hydroxycarboxylic acids were detected. All of these compounds except 1,3-propanediol and 1,3-butanediol have been identified in the Murchison and Bell meteorites. The most abundant species, ethylene glycol, has also been found in the ISM.Our findings suggest that other polyols and acids may also be present in methanol-rich starforming regions. The non-detection of higher order sugars, as those found in the ultraviolet (UV) photon processed 13 C-methanol ( 13 CH3OH):water (H2O):ammonia (NH3) and 13 C-methanol ( 13 CH3OH):water (H2O) ice mixtures, indicates that the type of radiation source or more likely the prevalent NH3 and/or H2O molecules in the ISM are critical to the abiotic formation of the bio-essential sugars. Experiments are currently being designed to elucidate the roles of each component.

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“…Additionally, methanol, a Article number, page 1 of 17 arXiv:2002.06971v1 [astro-ph.SR] 17 Feb 2020 A&A proofs: manuscript no. C2H2+OH fully hydrogen-saturated derivative of CO, is also regarded as a starting point in the formation of COMs upon "energetic" processing via the interaction of UV-photons, cosmic particles, and X-rays (Gerakines et al 1996;Moore et al 1996;Garrod et al 2006;Öberg et al 2009;Modica & Palumbo 2010;Chen et al 2013;Boamah et al 2014;Maity et al 2015;Henderson & Gudipati 2015;Paardekooper et al 2016;Chuang et al 2017;Rothard et al 2017). These solid-state laboratory studies of energetic and nonenergetic scenarios all suggest an icy origin of COMs in starforming regions.…”

Section: Introductionmentioning

confidence: 99%

Formation of complex molecules in translucent clouds: acetaldehyde, vinyl alcohol, ketene, and ethanol via “nonenergetic” processing of C₂H₂ice

Chuang

Fedoseev

Qasim

et al. 2020

A&A

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Context. Complex organic molecules (COMs) have been identified toward high-and low-mass protostars as well as molecular clouds, suggesting that these interstellar species originate from the early stage(s) of starformation. The reaction pathways resulting in COMs described by the formula C 2 H n O, such as acetaldehyde (CH 3 CHO), vinyl alcohol (CH 2 CHOH), ketene (CH 2 CO), and ethanol (CH 3 CH 2 OH), are still under debate. Several of these species have been detected in both translucent and dense clouds, where chemical processes are dominated by (ground-state) atom and radical surface reactions. Therefore, efficient formation pathways are needed to account for their appearance well before the so-called catastrophic CO freeze-out stage starts. Aims. In this work, we investigate the laboratory possible solid-state reactions that involve simple hydrocarbons and OH-radicals along with H 2 O ice under translucent cloud conditions (1≤A V ≤5 and n H ∼10 3 cm −3 ). We focus on the interactions of C 2 H 2 with H-atoms and OH-radicals, which are produced along the H 2 O formation sequence on grain surfaces at 10 K. Methods. Ultra-high vacuum (UHV) experiments were performed to study the surface chemistry observed during C 2 H 2 + O 2 + H codeposition, where O 2 was used for the in-situ generation of OH-radicals. These C 2 H 2 experiments were extended by a set of similar experiments involving acetaldehyde (CH 3 CHO) -an abundant product of C 2 H 2 + O 2 + H codeposition. Reflection absorption infrared spectroscopy (RAIRS) was applied to in situ monitor the initial and newly formed species. After that, a temperature-programmed desorption experiment combined with a Quadrupole mass spectrometer (TPD-QMS) was used as a complementary analytical tool. The IR and QMS spectral assignments were further confirmed in isotope labeling experiments using 18 O 2 . Results. The investigated 10 K surface chemistry of C 2 H 2 with H-atoms and OH-radicals not only results in semi and fully saturated hydrocarbons, such as ethylene (C 2 H 4 ) and ethane (C 2 H 6 ), but it also leads to the formation of COMs, such as vinyl alcohol, acetaldehyde, ketene, ethanol, and possibly acetic acid. It is concluded that OH-radical addition reactions to C 2 H 2 , acting as a molecular backbone, followed by isomerization (i.e., keto-enol tautomerization) via an intermolecular pathway and successive hydrogenation provides a so far experimentally unreported solid-state route for the formation of these species without the need of energetic input. The kinetics of acetaldehyde reacting with impacting H-atoms leading to ketene and ethanol is found to have a preference for the saturated product. The astronomical relevance of the reaction network introduced here is discussed.

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Soft X-Ray Irradiation of Methanol Ice: Formation of Products as a Function of Photon Energy

Cited by 55 publications

References 24 publications

Chemical Evolution of a Co Ice Induced by Soft X-Rays

Chemical Evolution of a Co Ice Induced by Soft X-Rays

On the Production of Polyols and Hydroxycarboxylic Acids in Interstellar Analogous Ices of Methanol

Formation of complex molecules in translucent clouds: acetaldehyde, vinyl alcohol, ketene, and ethanol via “nonenergetic” processing of C₂H₂ice

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Soft X-Ray Irradiation of Methanol Ice: Formation of Products as a Function of Photon Energy

Cited by 55 publications

References 24 publications

Chemical Evolution of a Co Ice Induced by Soft X-Rays

Chemical Evolution of a Co Ice Induced by Soft X-Rays

On the Production of Polyols and Hydroxycarboxylic Acids in Interstellar Analogous Ices of Methanol

Formation of complex molecules in translucent clouds: acetaldehyde, vinyl alcohol, ketene, and ethanol via “nonenergetic” processing of C2H2ice

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Formation of complex molecules in translucent clouds: acetaldehyde, vinyl alcohol, ketene, and ethanol via “nonenergetic” processing of C₂H₂ice