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Puzzarini C, Alessandrini S. Carbamic acid and its dimer: A computational study. J Comput Chem 2024. [PMID: 38970400 DOI: 10.1002/jcc.27442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 05/15/2024] [Accepted: 05/17/2024] [Indexed: 07/08/2024]
Abstract
A recent work by Marks et al. on the formation of carbamic acid in NH3 $$ {}_3 $$ -CO2 $$ {}_2 $$ interstellar ices pointed out its stability in the gas phase and the concomitant production of its dimer. Prompted by these results and the lack of information on these species, we have performed an accurate structural, energetic and spectroscopic investigation of carbamic acid and its dimer. For the former, the structural and spectroscopic characterization employed composite schemes based on coupled cluster (CC) calculations that account for the extrapolation to the complete basis set limit and core correlation effects. A first important outcome is the definitive confirmation of the nonplanarity of carbamic acid, then followed by an accurate estimate of its rotational and vibrational spectroscopy parameters. As far as the carbamic acid dimer is concerned, the investigation started from the identification of its most stable forms. For them, structure and vibrational properties have been evaluated using density functional theory, while a composite scheme rooted in CC theory has been employed for the energetic characterization. Our results allowed us to provide a better interpretation of the feature observed in the recent experiment mentioned above.
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Affiliation(s)
- Cristina Puzzarini
- Department of Chemistry "Giacomo Ciamician", University of Bologna, Bologna, Italy
| | - Silvia Alessandrini
- Department of Chemistry "Giacomo Ciamician", University of Bologna, Bologna, Italy
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2
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Marks J, Wang J, Sun BJ, McAnally M, Turner AM, Chang AHH, Kaiser RI. Thermal Synthesis of Carbamic Acid and Its Dimer in Interstellar Ices: A Reservoir of Interstellar Amino Acids. ACS CENTRAL SCIENCE 2023; 9:2241-2250. [PMID: 38161363 PMCID: PMC10755733 DOI: 10.1021/acscentsci.3c01108] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 10/13/2023] [Accepted: 10/19/2023] [Indexed: 01/03/2024]
Abstract
Reactions in interstellar ices are shown to be capable of producing key prebiotic molecules without energetic radiation that are necessary for the origins of life. When present in interstellar ices, carbamic acid (H2NCOOH) can serve as a condensed-phase source of the molecular building blocks for more complex proteinogenic amino acids. Here, Fourier transform infrared spectroscopy during heating of analogue interstellar ices composed of carbon dioxide and ammonia identifies the lower limit for thermal synthesis to be 62 ± 3 K for carbamic acid and 39 ± 4 K for its salt ammonium carbamate ([H2NCOO-][NH4+]). While solvation increases the rates of formation and decomposition of carbamic acid in ice, the absence of solvent effects after sublimation results in a significant barrier to dissociation and a stable gas-phase molecule. Photoionization reflectron time-of-flight mass spectrometry permits an unprecedented degree of sensitivity toward gaseous carbamic acid and demonstrates sublimation of carbamic acid from decomposition of ammonium carbamate and again at higher temperatures from carbamic acid dimers. Since the dimer is observed at temperatures up to 290 K, similar to the environment of a protoplanetary disk, this dimer is a promising reservoir of amino acids during the formation of stars and planets.
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Affiliation(s)
- Joshua
H. Marks
- W.
M. Keck Research Laboratory in Astrochemistry, University of Hawai’i at Manoa, Honolulu, Hawaii 96822, United States
- Department
of Chemistry, University of Hawai’i
at Manoa, Honolulu, Hawaii 96822, United States
| | - Jia Wang
- W.
M. Keck Research Laboratory in Astrochemistry, University of Hawai’i at Manoa, Honolulu, Hawaii 96822, United States
- Department
of Chemistry, University of Hawai’i
at Manoa, Honolulu, Hawaii 96822, United States
| | - Bing-Jian Sun
- Department
of Chemistry, National Dong Hwa University, Hualien 974, Taiwan
| | - Mason McAnally
- W.
M. Keck Research Laboratory in Astrochemistry, University of Hawai’i at Manoa, Honolulu, Hawaii 96822, United States
- Department
of Chemistry, University of Hawai’i
at Manoa, Honolulu, Hawaii 96822, United States
| | - Andrew M. Turner
- W.
M. Keck Research Laboratory in Astrochemistry, University of Hawai’i at Manoa, Honolulu, Hawaii 96822, United States
- Department
of Chemistry, University of Hawai’i
at Manoa, Honolulu, Hawaii 96822, United States
| | - Agnes H.-H. Chang
- Department
of Chemistry, National Dong Hwa University, Hualien 974, Taiwan
| | - Ralf I. Kaiser
- W.
M. Keck Research Laboratory in Astrochemistry, University of Hawai’i at Manoa, Honolulu, Hawaii 96822, United States
- Department
of Chemistry, University of Hawai’i
at Manoa, Honolulu, Hawaii 96822, United States
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Sangeetha E, Narayanan A, Dhamodharan R. Super water-absorbing hydrogel based on chitosan, itaconic acid and urea: preparation, characterization and reversible water absorption. Polym Bull (Berl) 2022. [DOI: 10.1007/s00289-021-03641-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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4
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Potapov A, Fulvio D, Krasnokutski S, Jäger C, Henning T. Formation of Complex Organic and Prebiotic Molecules in H 2O:NH 3:CO 2 Ices at Temperatures Relevant to Hot Cores, Protostellar Envelopes, and Planet-Forming Disks. J Phys Chem A 2022; 126:1627-1639. [PMID: 35245052 DOI: 10.1021/acs.jpca.1c10188] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Photochemistry in H2O:NH3:CO2 cosmic ice analogues was studied at temperatures of 75, 120, and 150 K, relevant to hot cores and warmer regions in protostellar envelopes and planet-forming disks. A combination of two triggers of surface chemistry in cosmic ice analogues, heat and UV irradiation, compared to using either just heat or UV irradiation, leads to a larger variety and an increased production of complex organic molecules, including potential precursors of prebiotic molecules. In addition to complex organic molecules detected in previous studies of H2O:NH3:CO2 ices, ammonium carbamate, carbamic acid, ammonium formate and formamide, we detected acetaldehyde, urea, and, tentatively, glycine, the simplest amino acid. Water ice hampers reactions at low temperature (75 K) but allows the parent molecules, CO2 and NH3, to stay in the solid state and react at higher temperatures (120 and 150 K, above their desorption temperatures). The experiments were performed on the surface of KBr substrates and amorphous silicate grains, analogs of cosmic silicate dust. The production of complex molecules on the silicate surface is decreased compared to KBr. This result suggests that the larger surface area and/or surface properties of the silicate grains play a role in controlling the chemistry, preventing it taking place to the same extent as on the flat KBr substrate. This is further evidence of the fact that cosmic dust grains play an important role in the chemistry taking place on their surface.
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Affiliation(s)
- Alexey Potapov
- Laboratory Astrophysics Group of the Max Planck Institute for Astronomy at the Friedrich Schiller University Jena, Institute of Solid State Physics, Helmholtzweg 3, 07743 Jena, Germany
| | - Daniele Fulvio
- Osservatorio Astronomico di Capodimonte, Istituto Nazionale di Astrofisica, Salita Moiariello 16, 80131, Naples, Italy.,Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg, Germany
| | - Serge Krasnokutski
- Laboratory Astrophysics Group of the Max Planck Institute for Astronomy at the Friedrich Schiller University Jena, Institute of Solid State Physics, Helmholtzweg 3, 07743 Jena, Germany
| | - Cornelia Jäger
- Laboratory Astrophysics Group of the Max Planck Institute for Astronomy at the Friedrich Schiller University Jena, Institute of Solid State Physics, Helmholtzweg 3, 07743 Jena, Germany
| | - Thomas Henning
- Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg, Germany
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5
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Govindaraj P, Raghavachari D. Fabrication of macroporous soft hydrogels of Chitosan scaffolds by hydrothermal reaction and cytotoxicity to 3T3 L1 cells. JOURNAL OF POLYMER RESEARCH 2021. [DOI: 10.1007/s10965-021-02426-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Govindaraj P, Subramanian S, Raghavachari D. Preparation of gels of chitosan through a hydrothermal reaction in the presence of malonic acid and cinnamaldehyde: characterization and antibacterial activity. NEW J CHEM 2021. [DOI: 10.1039/d1nj04149e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The preparation of composite gels through the hydrothermal reaction of a mixture of chitosan (CH), malonic acid (MLA), urea (UR) and cinnamaldehyde (CA), all of which are sustainable materials, is reported.
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Affiliation(s)
- Prabha Govindaraj
- Department of Applied Science & Technology, Alagappa College of Technology, Anna University, Chennai 600 025, India
| | - Sivanesan Subramanian
- Department of Applied Science & Technology, Alagappa College of Technology, Anna University, Chennai 600 025, India
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7
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James RL, Ioppolo S, Hoffmann SV, Jones NC, Mason NJ, Dawes A. Systematic investigation of CO 2 : NH 3 ice mixtures using mid-IR and VUV spectroscopy – part 2: electron irradiation and thermal processing. RSC Adv 2021; 11:33055-33069. [PMID: 35493573 PMCID: PMC9042239 DOI: 10.1039/d1ra05600j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 09/20/2021] [Indexed: 11/21/2022] Open
Abstract
Many experimental parameters determine the chemical and physical properties of interstellar ice analogues, each of which may influence the molecular synthesis that occurs in such ices. In part 1, James et al., RSC Adv., 2020, 10, 37517, we demonstrated the effects that the stoichiometric mixing ratio had on the chemical and physical properties of CO2 : NH3 mixtures and the impact on molecular synthesis induced by thermal processing. Here, in part 2, we extend this to include 1 keV electron irradiation at 20 K of several stoichiometric mixing ratios of CO2 : NH3 ices followed by thermal processing. We demonstrate that not all stoichiometric mixing ratios of CO2 : NH3 ice form the same products. Not only did the 4 : 1 ratio form a different residue after thermal processing, but O3 was observed after electron irradiation at 20 K, which was not observed in the other ratios. For the other ratios, the residue formed from a thermal reaction similar to the work shown in Part 1. However, conversion of ammonium carbamate to carbamic acid was hindered due to electron irradiation at 20 K. Our results demonstrate the need to systematically investigate stoichiometric mixing ratios to better characterise the chemical and physical properties of interstellar ice analogues to further our understanding of the routes of molecular synthesis under different astrochemical conditions. The stoichiometric mixing ratio of CO2 : NH3 ice mixtures determines the electron irradiation products at 20 K and the composition of residue material formed after thermal processing.![]()
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Affiliation(s)
- Rachel L. James
- School of Physical Sciences, The Open University, Walton Hall, Milton Keynes, UK
| | - Sergio Ioppolo
- School of Electronic Engineering and Computer Science, Queen Mary University of London, Mile End Road, London, UK
| | - Søren V. Hoffmann
- ISA, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark
| | - Nykola C. Jones
- ISA, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark
| | - Nigel J. Mason
- School of Physical Sciences, University of Kent, Canterbury, Kent, UK
| | - Anita Dawes
- School of Physical Sciences, The Open University, Walton Hall, Milton Keynes, UK
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James RL, Ioppolo S, Hoffmann SV, Jones NC, Mason NJ, Dawes A. Systematic investigation of CO 2 : NH 3 ice mixtures using mid-IR and VUV spectroscopy - part 1: thermal processing. RSC Adv 2020; 10:37515-37528. [PMID: 35521284 PMCID: PMC9057146 DOI: 10.1039/d0ra05826b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 09/25/2020] [Indexed: 12/24/2022] Open
Abstract
The adjustment of experimental parameters in interstellar ice analogues can have profound effects on molecular synthesis within an ice system. We demonstrated this by systematically investigating the stoichiometric mixing ratios of CO2 : NH3 ices as a function of thermal processing using mid-IR and VUV spectroscopy. We observed that the type of CO2 bonding environment was dependent on the different stoichiometric mixing ratios and that this pre-determined the NH3 crystallite structure after phase change. The thermal reactivity of the ices was linked to the different chemical and physical properties of the stoichiometric ratios. Our results provide new details into the chemical and physical properties of the different stoichiometric CO2 : NH3 ices enhancing our understanding of the thermally induced molecular synthesis within this ice system.
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Affiliation(s)
- Rachel L James
- School of Physical Sciences, The Open University Walton Hall Milton Keynes UK +44 (0)1908 654192 +44 (0)1908 332012
| | - Sergio Ioppolo
- School of Electronic Engineering and Computer Science, Queen Mary University of London Mile End Road London UK
| | - Søren V Hoffmann
- ISA, Department of Physics and Astronomy, Aarhus University Ny Munkegade 120 DK-8000 Aarhus C Denmark
| | - Nykola C Jones
- ISA, Department of Physics and Astronomy, Aarhus University Ny Munkegade 120 DK-8000 Aarhus C Denmark
| | - Nigel J Mason
- School of Physical Sciences, University of Kent Canterbury Kent UK
| | - Anita Dawes
- School of Physical Sciences, The Open University Walton Hall Milton Keynes UK +44 (0)1908 654192 +44 (0)1908 332012
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9
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Govindaraj P, Abathodharanan N, Ravishankar K, Raghavachari D. Facile preparation of biocompatible macroporous chitosan hydrogel by hydrothermal reaction of a mixture of chitosan-succinic acid-urea. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2019; 104:109845. [DOI: 10.1016/j.msec.2019.109845] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 05/13/2019] [Accepted: 05/30/2019] [Indexed: 10/26/2022]
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10
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Altun Z, Bleda E, Trindle C. Production of Carbamic Acid Dimer from Ammonia-Carbon Dioxide Ices: Matching Observed and Computed IR Spectra. Life (Basel) 2019; 9:life9020034. [PMID: 31018481 PMCID: PMC6617078 DOI: 10.3390/life9020034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 04/19/2019] [Accepted: 04/19/2019] [Indexed: 11/16/2022] Open
Abstract
The production of complex molecules in ammonia–carbon dioxide ices is presumed to pass through species of formula H3N:CO2 with further addition of ammonia and carbon dioxide. One possible landmark, carbamic acid, H2NCOOH, has been implicated among the products of warming and irradiation of such ices. Experimental study of the IR spectra of residues has suggested the presence of related species, including weakly bound 1:1 and 2:1 complexes of ammonia with carbon dioxide, zwitterionic carbamic acid, ammonium carbamate, and the dimer of carbamic acid. We computed the energetics and vibrational spectra of these species as well as the complex between ammonia and carbamic acid for gas and condensed phases. By means of a new spectrum-matching scoring between computed and observed vibrational spectra, we infer species that are most probably present. The leading candidates are ammonium carbamate, the carbamic acid–ammonia complex, and the carbamic acid dimer.
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Affiliation(s)
- Zikri Altun
- Physics Department, Marmara University, Istanbul 34722, Turkey.
| | - Erdi Bleda
- Physics Department, Marmara University, Istanbul 34722, Turkey.
| | - Carl Trindle
- Chemistry Department, University of Virginia, Charlottesville 22902, VA, USA.
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11
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The formation of urea in space. II. MP2 versus PM6 dynamics in determining bimolecular reaction products. Theor Chem Acc 2018. [DOI: 10.1007/s00214-018-2385-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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12
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Kılıç M, Devlin JP, Uras-Aytemiz N. NH 3 as simple clathrate-hydrate catalyst: Experiment and theory. J Chem Phys 2018; 148:234501. [PMID: 29935504 DOI: 10.1063/1.5029908] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The catalytic action of NH3 within the all-vapor approach for instant clathrate hydrate (CH) formation is studied using both FTIR spectroscopy and ab initio molecular dynamics simulations. A unique property of NH3, namely, the rapid abundant penetration and occupation of the water network, creates defects, particularly Bjerrum D-defects, in the hydrate frame that are generally stabilized by guest NH3 molecules in the cages. Furthermore, insertion of NH3 seriously disturbs the hydrate network where the guest NH3 molecules also make fluxional H-bonds with the host water molecules. These defects strongly facilitate a sub-second formation of the simple NH3 s-II gas hydrate at 160 K. FTIR spectra of aerosols of the NH3 s-II CH have been measured, and the displacement of both small and large cage NH3 guests by CO2 and tetrahydrofuran is examined.
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Affiliation(s)
- Murat Kılıç
- Van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - J Paul Devlin
- Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma 74078, USA
| | - Nevin Uras-Aytemiz
- Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma 74078, USA
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13
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Esmaili S, Bass AD, Cloutier P, Sanche L, Huels MA. Glycine formation in CO 2:CH 4:NH 3 ices induced by 0-70 eV electrons. J Chem Phys 2018; 148:164702. [PMID: 29716196 DOI: 10.1063/1.5021596] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Glycine (Gly), the simplest amino-acid building-block of proteins, has been identified on icy dust grains in the interstellar medium, icy comets, and ice covered meteorites. These astrophysical ices contain simple molecules (e.g., CO2, H2O, CH4, HCN, and NH3) and are exposed to complex radiation fields, e.g., UV, γ, or X-rays, stellar/solar wind particles, or cosmic rays. While much current effort is focused on understanding the radiochemistry induced in these ices by high energy radiation, the effects of the abundant secondary low energy electrons (LEEs) it produces have been mostly assumed rather than studied. Here we present the results for the exposure of multilayer CO2:CH4:NH3 ice mixtures to 0-70 eV electrons under simulated astrophysical conditions. Mass selected temperature programmed desorption (TPD) of our electron irradiated films reveals multiple products, most notably intact glycine, which is supported by control measurements of both irradiated or un-irradiated binary mixture films, and un-irradiated CO2:CH4:NH3 ices spiked with Gly. The threshold of Gly formation by LEEs is near 9 eV, while the TPD analysis of Gly film growth allows us to determine the "quantum" yield for 70 eV electrons to be about 0.004 Gly per incident electron. Our results show that simple amino acids can be formed directly from simple molecular ingredients, none of which possess preformed C-C or C-N bonds, by the copious secondary LEEs that are generated by ionizing radiation in astrophysical ices.
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Affiliation(s)
- Sasan Esmaili
- Département de Médecine Nucléaire et Radiobiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, Quebec J1H5N4, Canada
| | - Andrew D Bass
- Département de Médecine Nucléaire et Radiobiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, Quebec J1H5N4, Canada
| | - Pierre Cloutier
- Département de Médecine Nucléaire et Radiobiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, Quebec J1H5N4, Canada
| | - Léon Sanche
- Département de Médecine Nucléaire et Radiobiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, Quebec J1H5N4, Canada
| | - Michael A Huels
- Département de Médecine Nucléaire et Radiobiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, Quebec J1H5N4, Canada
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14
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Maşlakcı Z, Devlin JP, Uras-Aytemiz N. NH 3 as unique non-classical content-former within clathrate hydrates. J Chem Phys 2017. [PMID: 28641420 DOI: 10.1063/1.4985668] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
High quality FTIR spectra of aerosols of NH3-THF and NH3-TMO binary clathrate hydrates (CHs) have been measured. Our recently developed all-vapor sub-second approach to clathrate-hydrate formation combined with computational studies has been used to identify vibrational spectroscopic signatures of NH3 within the gas hydrates. The present study shows that there are three distinct NH3 types, namely, classical small-cage NH3, nonclassical small-cage NH3, and NH3 within the hydrate network. The network ammonia does not directly trigger the non-classical CH structure. Rather, the ammonia within the network structure perturbs the water bonding, introducing orientational defects that are stabilized by small and/or large cage guest molecules through H-bonding. This unusual behavior of NH3 within CHs opens a possibility for catalytic action of NH3 during CH-formation. Furthermore, impacts over time of the small-cage NH3-replacement molecules CO2 and CH4 on the structure and composition of the ternary CHs have been noted.
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Affiliation(s)
- Zafer Maşlakcı
- Department of Chemistry, Karabuk University, 78050 Karabuk, Turkey
| | - J Paul Devlin
- Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma 74078, USA
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15
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Vinogradoff V, Duvernay F, Fray N, Bouilloud M, Chiavassa T, Cottin H. CARBON DIOXIDE INFLUENCE ON THE THERMAL FORMATION OF COMPLEX ORGANIC MOLECULES IN INTERSTELLAR ICE ANALOGS. ACTA ACUST UNITED AC 2015. [DOI: 10.1088/2041-8205/809/2/l18] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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16
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Noble JA, Theule P, Duvernay F, Danger G, Chiavassa T, Ghesquiere P, Mineva T, Talbi D. Kinetics of the NH3 and CO2 solid-state reaction at low temperature. Phys Chem Chem Phys 2014; 16:23604-15. [PMID: 25198107 DOI: 10.1039/c4cp02414a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Ammonia and carbon dioxide play an important role in both atmospheric and interstellar ice chemistries. This work presents a theoretical and experimental study of the kinetics of the low-temperature NH3 and CO2 solid-state reaction in ice films, the product of which is ammonium carbamate (NH4(+)NH2COO(-)). It is a first-order reaction with respect to CO2, with a temperature-dependent rate constant fitted to the Arrhenius law in the temperature range 70 K to 90 K, with an activation energy of 5.1 ± 1.6 kJ mol(-1) and a pre-exponential factor of 0.09-0.08(+1.1) s(-1). This work helps to determine the rate of removal of CO2 and NH3, via their conversion into ammonium carbamate, from atmospheric and interstellar ices. We also measure first-order desorption energies of 69.0 ± 0.2 kJ mol(-1) and 76.1 ± 0.1 kJ mol(-1), assuming a pre-exponential factor of 10(13) s(-1), for ammonium carbamate and carbamic acid, respectively.
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Affiliation(s)
- J A Noble
- Aix-Marseille Univ., CNRS, PIIM UMR 7345, Marseille, 13397, France.
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