Extension of the HCOOH and CO2 solid-state reaction network during the CO freeze-out stage: inclusion of H2CO

Context. Formic acid (HCOOH) and carbon dioxide (CO2) are simple species that have been detected in the interstellar medium. The solid-state formation pathways of these species under experimental conditions relevant to prestellar cores are primarily based off of weak infrared transitions of the HOCO complex and usually pertain to the H2O-rich ice phase, and therefore more experimental data are desired. Aims. Here, we present a new and additional solid-state reaction pathway that can form HCOOH and CO2 ice at 10 K “non-energetically” in the laboratory under conditions related to the “heavy” CO freeze-out stage in dense interstellar clouds, i.e., by the hydrogenation of an H2CO:O2 ice mixture. This pathway is used to piece together the HCOOH and CO2 formation routes when H2CO or CO reacts with H and OH radicals. Methods. Temperature programmed desorption – quadrupole mass spectrometry (TPD-QMS) is used to confirm the formation and pathways of newly synthesized ice species as well as to provide information on relative molecular abundances. Reflection absorption infrared spectroscopy (RAIRS) is additionally employed to characterize reaction products and determine relative molecular abundances. Results. We find that for the conditions investigated in conjunction with theoretical results from the literature, H + HOCO and HCO + OH lead to the formation of HCOOH ice in our experiments. Which reaction is more dominant can be determined if the H + HOCO branching ratio is more constrained by computational simulations, as the HCOOH:CO2 abundance ratio is experimentally measured to be around 1.8:1. H + HOCO is more likely than OH + CO (without HOCO formation) to form CO2. Isotope experiments presented here further validate that H + HOCO is the dominant route for HCOOH ice formation in a CO-rich CO:O2 ice mixture that is hydrogenated. These data will help in the search and positive identification of HCOOH ice in prestellar cores.

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One-Step Simultaneous Differential Scanning Calorimetry-FTIR Microspectroscopy to Quickly Detect Continuous Pathways in the Solid-State Glucose/Asparagine Maillard Reaction

Journal of AOAC International ◽

10.5740/jaoacint.13-074 ◽

2013 ◽

Vol 96 (6) ◽

pp. 1362-1364 ◽

Cited By ~ 1

Author(s):

Deng-Fwu Hwang ◽

Tzu-Feng Hsieh ◽

Shan-Yang Lin

Keyword(s):

Differential Scanning Calorimetry ◽

Solid State ◽

Maillard Reaction ◽

Reaction Pathway ◽

Molar Ratio ◽

Maillard Reaction Products ◽

Reaction Products ◽

Scanning Calorimetry ◽

Ftir Microspectroscopy ◽

Amadori Product

Abstract The stepwise reaction pathway of the solid-state Maillard reaction between glucose (Glc) and asparagine (Asn) was investigated using simultaneous differential scanning calorimetry (DSC)-FTIR microspectroscopy. The color change and FTIR spectra of Glc-Asn physical mixtures (molar ratio = 1:1) preheated to different temperatures followed by cooling were also examined. The successive reaction products such as Schiff base intermediate, Amadori product, and decarboxylated Amadori product in the solid-state Glc-Asn Maillard reaction were first simultaneously evidenced by this unique DSC-FTIR microspectroscopy. The color changed from white to yellow-brown to dark brown, and appearance of new IR peaks confirmed the formation of Maillard reaction products. The present study clearly indicates that this unique DSC-FTIR technique not only accelerates but also detects precursors and products of the Maillard reaction in real time.

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Raman characterization of α- and β-LiFe5O8 prepared through a solid-state reaction pathway

Journal of Solid State Chemistry ◽

10.1016/j.jssc.2009.11.011 ◽

2010 ◽

Vol 183 (2) ◽

pp. 322-326 ◽

Cited By ~ 23

Author(s):

W. Cook ◽

M. Manley

Keyword(s):

Solid State ◽

Solid State Reaction ◽

Reaction Pathway ◽

Raman Characterization

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Infrared reflectivity spectra of the reaction products KxMoO3(x=0.1-0.5) prepared by a solid state reaction

Journal of Physics Condensed Matter ◽

10.1088/0953-8984/2/23/010 ◽

1990 ◽

Vol 2 (23) ◽

pp. 5199-5217 ◽

Cited By ~ 3

Author(s):

T Hirata ◽

K Yagisawa

Keyword(s):

Solid State ◽

Solid State Reaction ◽

Reaction Products ◽

Infrared Reflectivity ◽

Reflectivity Spectra

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Formation of interstellar methanol ice prior to the heavy CO freeze-out stage

Astronomy and Astrophysics ◽

10.1051/0004-6361/201732355 ◽

2018 ◽

Vol 612 ◽

pp. A83 ◽

Cited By ~ 8

Author(s):

D. Qasim ◽

K.-J. Chuang ◽

G. Fedoseev ◽

S. Ioppolo ◽

A. C. A. Boogert ◽

...

Keyword(s):

Surface Reaction ◽

Oh Radicals ◽

Quadrupole Mass ◽

Hydrogen Atoms ◽

Experimental Conditions ◽

Interstellar Ice ◽

Reflection Absorption Infrared Spectroscopy ◽

Temperature Programmed ◽

Reaction Chain ◽

Freeze Out

Context. The formation of methanol (CH3OH) on icy grain mantles during the star formation cycle is mainly associated with the CO freeze-out stage. Yet there are reasons to believe that CH3OH also can form at an earlier period of interstellar ice evolution in CO-poor and H2O-rich ices. Aims. This work focuses on CH3OH formation in a H2O-rich interstellar ice environment following the OH-mediated H-abstraction in the reaction, CH4 + OH. Experimental conditions are systematically varied to constrain the CH3OH formation yield at astronomically relevant temperatures. Methods. CH4, O2, and hydrogen atoms are co–deposited in an ultrahigh vacuum chamber at 10–20 K. OH radicals are generated by the H + O2 surface reaction. Temperature programmed desorption – quadrupole mass spectrometry (TPD–QMS) is used to characterize CH3OH formation, and is complemented with reflection absorption infrared spectroscopy (RAIRS) for CH3OH characterization and quantitation. Results. CH3OH formation is shown to be possible by the sequential surface reaction chain, CH4 + OH → CH3 + H2O and CH3 + OH → CH3OH at 10–20 K. This reaction is enhanced by tunneling, as noted in a recent theoretical investigation Lamberts et al. (2017, A&A, 599, A132). The CH3OH formation yield via the CH4 + OH route versus the CO + H route is approximately 20 times smaller for the laboratory settings studied. The astronomical relevance of the new formation channel investigated here is discussed.

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Ion-Beam Mixing and Solid-State Reaction in Zr-Fe Multilayers

MRS Proceedings ◽

10.1557/proc-439-419 ◽

1996 ◽

Vol 439 ◽

Cited By ~ 1

Author(s):

A. Paesano ◽

A. T. Motta ◽

R. C. Birtcher ◽

E. A. Ryan ◽

S. R. Teixeira ◽

...

Keyword(s):

Solid State ◽

Amorphous Phase ◽

Solid State Reaction ◽

Ion Beam ◽

National Laboratory ◽

Argonne National Laboratory ◽

Reaction Products ◽

Phase Selection ◽

Voltage Electron ◽

Multilayered Thin Films

AbstractVapor-deposited Zr-Fe multilayered thin films with various wavelengths and of overall composition either 50% Fe or Fe-rich up to 57 % Fe were either irradiated with 300 keV Kr ions at temperatures from 25K to 623 K to fluences up to 2 × 1016 cm−2, or simply annealed at 773K in-situ in the Intermediate Voltage Electron Microscope at Argonne National Laboratory. Under irradiation, the final reaction product is the amorphous phase in all cases studied, but the dose to amorphization depends on the temperature and on the wavelength. In the purely thermal case (annealing at 773 K), the 50–50 composition produces the amorphous phase but for the Fe-rich multilayers the reaction products depend on the multilayer wavelength. For small wavelength, the amorphous phase is still formed, but at large wavelength the Zr-Fe crystalline intermetallic compounds appear. These results are discussed in terms of existing models of irradiation kinetics and phase selection during solid state reaction.

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Reaction between 8-Hydroxyquinoline and Salicylic Acid in Solid State and Solution

Zeitschrift für Physikalische Chemie ◽

10.1524/zpch.2000.214.2.179 ◽

2000 ◽

Vol 214 (2) ◽

Cited By ~ 2

Author(s):

N.B. Singh ◽

R. Singh ◽

K. Singh

Keyword(s):

Salicylic Acid ◽

Solid State ◽

Solid State Reaction ◽

Structural Changes ◽

Crystal Packing ◽

Thermal Studies ◽

Structural Difference ◽

Spectroscopic Studies ◽

Product Layer ◽

Reaction Products

8-Hydroxyquinoline reacts with salicylic acid both in solid state and solution forming a yellow coloured compound. Phase diagram studies have shown the formation of a 1:1 addition compound stable in solid state and dissociated in solution. Differential thermal studies have shown that the reaction products obtained from solution and solid state reaction are almost identical except that there is a possibility of entrapped solvent molecules when the product was prepared from benzene. Also the reaction product shows a thermochromic effect. X-ray diffraction studies have revealed some structural difference between the reaction product obtained from solution and solid state reaction. Spectroscopic studies show the possibility of hydrogen bonding in the reaction product.The reaction in the solid state is slow and once a thin layer of reaction product is formed at the surface of salicylic acid crystals, the reaction rate becomes practically negligible. This may be due to the compactness of the product layer and unfavourable crystal packing in to the crystal lattice of salicylic acid. Microstructural studies have shown that there are structural changes during solid state reaction.

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The influence of experimental conditions on the size and shape of crystallites produced by a solid state reaction. Case of Cd(OH)2 decomposition into CdO

Journal of Solid State Chemistry ◽

10.1016/0022-4596(79)90174-9 ◽

1979 ◽

Vol 27 (3) ◽

pp. 317-327 ◽

Cited By ~ 13

Author(s):

P. Dumas ◽

N. Ea ◽

J.C. Niepce ◽

G. Watelle

Keyword(s):

Solid State ◽

Solid State Reaction ◽

Experimental Conditions ◽

Size And Shape

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Photolysis and oxidation by OH radicals of two carbonyl nitrates: 4-nitrooxy-2-butanone and 5-nitrooxy-2-pentanone

Atmospheric Chemistry and Physics ◽

10.5194/acp-20-487-2020 ◽

2020 ◽

Vol 20 (1) ◽

pp. 487-498 ◽

Cited By ~ 1

Author(s):

Bénédicte Picquet-Varrault ◽

Ricardo Suarez-Bertoa ◽

Marius Duncianu ◽

Mathieu Cazaunau ◽

Edouard Pangui ◽

...

Keyword(s):

Cross Sections ◽

Rate Constants ◽

Branching Ratio ◽

Quantum Yields ◽

Organic Nitrates ◽

Oh Radicals ◽

Experimental Conditions ◽

Important Species ◽

Photolysis Rates ◽

Photolysis Frequencies

Abstract. Multifunctional organic nitrates, including carbonyl nitrates, are important species formed in NOx-rich atmospheres by the degradation of volatile organic compounds (VOCs). These compounds have been shown to play a key role in the transport of reactive nitrogen and, consequently, in the ozone budget; they are also known to be important components of the total organic aerosol. However, very little is known about their reactivity in both the gas and condensed phases. Following a previous study that we published on the gas-phase reactivity of α-nitrooxy ketones, the photolysis and reaction with OH radicals of 4-nitrooxy-2-butanone and 5-nitrooxy-2-pentanone (which are a β-nitrooxy ketone and γ-nitrooxy ketone, respectively) were investigated for the first time in simulation chambers. The photolysis frequencies were directly measured in the CESAM chamber, which is equipped with a very realistic irradiation system. The jnitrate/jNO2 ratios were found to be (5.9±0.9)×10-3 for 4-nitrooxy-2-butanone and (3.2±0.9)×10-3 for 5-nitrooxy-2-pentanone under our experimental conditions. From these results, it was estimated that ambient photolysis frequencies calculated for typical tropospheric irradiation conditions corresponding to the 1 July at noon at 40∘ N (overhead ozone column of 300 and albedo of 0.1) are (6.1±0.9)×10-5 s−1 and (3.3±0.9)×10-5 s−1 for 4-nitrooxy-2-butanone and 5-nitrooxy-2-pentanone, respectively. These results demonstrate that photolysis is a very efficient sink for these compounds with atmospheric lifetimes of few hours. They also suggest that, similarly to α-nitrooxy ketones, β-nitrooxy ketones have enhanced UV absorption cross sections and quantum yields equal to or close to unity and that γ-nitrooxy ketones have a lower enhancement of cross sections, which can easily be explained by the larger distance between the two chromophore groups. Thanks to a product study, the branching ratio between the two possible photodissociation pathways is also proposed. Rate constants for the reaction with OH radicals were found to be (2.9±1.0)×10-12 and (3.3±0.9)×10-12 cm3 molecule−1 s−1, respectively. These experimental data are in good agreement with rate constants estimated by the structure–activity relationship (SAR) of Kwok and Atkinson (1995) when using the parametrization proposed by Suarez-Bertoa et al. (2012) for carbonyl nitrates. Comparison with photolysis rates suggests that the OH-initiated oxidation of carbonyl nitrates is a less efficient sink than photodissociation but is not negligible in polluted areas.

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