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Carvalho GA, Pilling S. Chemical changes induced during heating of acetonitrile-rich ice pre-irradiated by X-rays and its implication in astrochemistry. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 267:120495. [PMID: 34700156 DOI: 10.1016/j.saa.2021.120495] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 09/20/2021] [Accepted: 10/09/2021] [Indexed: 06/13/2023]
Abstract
In this work, we investigate the effects induced by the heating of acetonitrile-rich ice from 13 K to 350 K. Before the heating, the sample was irradiated at 13 K by broadband X-rays (6 eV to 2 keV), which trigger the production of new molecules, such as HCN, H2CCNH, CH4 and CH3NC (see Carvalho and Pilling, 2020) and also induced desorption of frozen species to gas-phase. New spectra were collected during heating to investigate whether new species, not present before at lower temperatures, appear due to thermal processing. New infrared bands were identified at temperatures around 120 K and 300 K, from which it was possible to notice the possible presence of HCN/CN radical, ammonia and C2N2. It was also verified that acetonitrile has a thermal desorption peak between 120 K and 200 K, which yields to the vanishing of acetonitrile within the sample for temperatures of 200 K and above. Some infrared features assigned before solely to acetonitrile remain for sample temperatures >200 K, which indicates the presence of blended species with similar infrared features. From analyzing those blended peaks, we also perceived the possible presence of aminoacetonitrile.
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Affiliation(s)
- Geanderson A Carvalho
- Instituto de Pesquisa e Desenvolvimento (IP&D), Universidade do Vale do Paraíba (UNIVAP), Av. Shishima Hifumi 2911, São José dos Campos 12244-000, São Paulo, Brazil.
| | - Sérgio Pilling
- Instituto de Pesquisa e Desenvolvimento (IP&D), Universidade do Vale do Paraíba (UNIVAP), Av. Shishima Hifumi 2911, São José dos Campos 12244-000, São Paulo, Brazil
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Semushkina GI, Fedoseeva YV, Makarova AA, Smirnov DA, Asanov IP, Pinakov DV, Chekhova GN, Okotrub AV, Bulusheva LG. Photolysis of Fluorinated Graphites with Embedded Acetonitrile Using a White-Beam Synchrotron Radiation. NANOMATERIALS 2022; 12:nano12020231. [PMID: 35055249 PMCID: PMC8779973 DOI: 10.3390/nano12020231] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/04/2022] [Accepted: 01/05/2022] [Indexed: 02/05/2023]
Abstract
Fluorinated graphitic layers with good mechanical and chemical stability, polar C–F bonds, and tunable bandgap are attractive for a variety of applications. In this work, we investigated the photolysis of fluorinated graphites with interlayer embedded acetonitrile, which is the simplest representative of the acetonitrile-containing photosensitizing family. The samples were continuously illuminated in situ with high-brightness non-monochromatized synchrotron radiation. Changes in the compositions of the samples were monitored using X-ray photoelectron spectroscopy and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. The NEXAFS N K-edge spectra showed that acetonitrile dissociates to form HCN and N2 molecules after exposure to the white beam for 2 s, and the latter molecules completely disappear after exposure for 200 s. The original composition of fluorinated matrices CF0.3 and CF0.5 is changed to CF0.10 and GF0.17, respectively. The highly fluorinated layers lose fluorine atoms together with carbon neighbors, creating atomic vacancies. The edges of vacancies are terminated with the nitrogen atoms and form pyridinic and pyrrolic units. Our in situ studies show that the photolysis products of acetonitrile depend on the photon irradiation duration and composition of the initial CFx matrix. The obtained results evaluate the radiation damage of the acetonitrile-intercalated fluorinated graphites and the opportunities to synthesize nitrogen-doped graphene materials.
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Affiliation(s)
- Galina I. Semushkina
- Nikolaev Institute of Inorganic Chemistry SB RAS, 3, Acad. Lavrentiev Ave., 630090 Novosibirsk, Russia; (Y.V.F.); (I.P.A.); (D.V.P.); (G.N.C.); (A.V.O.)
- Correspondence: (G.I.S.); (L.G.B.)
| | - Yuliya V. Fedoseeva
- Nikolaev Institute of Inorganic Chemistry SB RAS, 3, Acad. Lavrentiev Ave., 630090 Novosibirsk, Russia; (Y.V.F.); (I.P.A.); (D.V.P.); (G.N.C.); (A.V.O.)
| | - Anna A. Makarova
- Physikalische Chemie, Institut für Chemie und Biochemie, Freie Universität Berlin, 14195 Berlin, Germany;
| | - Dmitry A. Smirnov
- Institut für Festkörper- und Materialphysik, Technische Universität Dresden, 01069 Dresden, Germany;
| | - Igor P. Asanov
- Nikolaev Institute of Inorganic Chemistry SB RAS, 3, Acad. Lavrentiev Ave., 630090 Novosibirsk, Russia; (Y.V.F.); (I.P.A.); (D.V.P.); (G.N.C.); (A.V.O.)
| | - Dmitry V. Pinakov
- Nikolaev Institute of Inorganic Chemistry SB RAS, 3, Acad. Lavrentiev Ave., 630090 Novosibirsk, Russia; (Y.V.F.); (I.P.A.); (D.V.P.); (G.N.C.); (A.V.O.)
| | - Galina N. Chekhova
- Nikolaev Institute of Inorganic Chemistry SB RAS, 3, Acad. Lavrentiev Ave., 630090 Novosibirsk, Russia; (Y.V.F.); (I.P.A.); (D.V.P.); (G.N.C.); (A.V.O.)
| | - Alexander V. Okotrub
- Nikolaev Institute of Inorganic Chemistry SB RAS, 3, Acad. Lavrentiev Ave., 630090 Novosibirsk, Russia; (Y.V.F.); (I.P.A.); (D.V.P.); (G.N.C.); (A.V.O.)
| | - Lyubov G. Bulusheva
- Nikolaev Institute of Inorganic Chemistry SB RAS, 3, Acad. Lavrentiev Ave., 630090 Novosibirsk, Russia; (Y.V.F.); (I.P.A.); (D.V.P.); (G.N.C.); (A.V.O.)
- Correspondence: (G.I.S.); (L.G.B.)
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Feldman VI, Ryazantsev SV, Kameneva SV. Matrix isolation in laboratory astrochemistry: state-of-the-art, implications and perspective. RUSSIAN CHEMICAL REVIEWS 2021. [DOI: 10.1070/rcr4995] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Cerqueira HBA, Santos JC, Fantuzzi F, Ribeiro FDA, Rocco MLM, Oliveira RR, Rocha AB. Structure, Stability, and Spectroscopic Properties of Small Acetonitrile Cation Clusters. J Phys Chem A 2020; 124:6845-6855. [PMID: 32702984 DOI: 10.1021/acs.jpca.0c03529] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ionization and fragmentation pathways induced by ionizing agents are key to understanding the formation of complex molecules in astrophysical environments. Acetonitrile (CH3CN), the simplest organic nitrile, is an important molecule present in the interstellar medium. In this work, DFT and MP2 calculations were performed in order to obtain the low energy structures of the most relevant cations formed from electron-stimulated ion desorption of CH3CN ices. Selected reaction pathways and spectroscopic properties were also calculated. Our results indicate that the most stable acetonitrile cation structure is CH2CNH+ and that hydrogenation can occur successively without isomerization steps until its complete saturation. Moreover, the stability of distinct cluster families formed from the interaction of acetonitrile with small fragments, such as CHn+, C2Hn+, and CHnCNH+, is discussed in terms of their respective binding energies. Some of these molecular clusters are stabilized by hydrogen bonds, leading to species whose infrared features are characterized by a strong redshift of the N-H stretching mode. Finally, the rotational spectra of CH3CN and protonated acetonitrile, CH3CNH+, were simulated using distinct computational protocols based on DFT, MP2, and CCSD(T) considering centrifugal distortion, vibrational-rotational coupling, and vibrational anharmonicity corrections. By adopting an empirical scaling procedure for calculating spectroscopic parameters, we were able to estimate the rotational frequencies of CH3CNH+ with an expected average error below 1 MHz for J values up to 10.
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Affiliation(s)
- Henrique B A Cerqueira
- Instituto de Quı́mica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-909, Brazil
| | - Julia C Santos
- Instituto de Quı́mica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-909, Brazil
| | - Felipe Fantuzzi
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.,Institut für Physikalische und Theoretische Chemie, Julius-Maximilians-Universität Würzburg, Emil-Fischer-Straße 42, 97074 Würzburg, Germany
| | | | - Maria Luiza M Rocco
- Instituto de Quı́mica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-909, Brazil
| | - Ricardo R Oliveira
- Instituto de Quı́mica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-909, Brazil
| | - Alexandre B Rocha
- Instituto de Quı́mica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-909, Brazil
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2018 Census of Interstellar, Circumstellar, Extragalactic, Protoplanetary Disk, and Exoplanetary Molecules. ACTA ACUST UNITED AC 2018. [DOI: 10.3847/1538-4365/aae5d2] [Citation(s) in RCA: 281] [Impact Index Per Article: 46.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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McGuire BA, Burkhardt AM, Kalenskii S, Shingledecker CN, Remijan AJ, Herbst E, McCarthy MC. Detection of the aromatic molecule benzonitrile (c-C6H5CN) in the interstellar medium. Science 2018; 359:202-205. [DOI: 10.1126/science.aao4890] [Citation(s) in RCA: 266] [Impact Index Per Article: 44.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 11/15/2017] [Indexed: 11/02/2022]
Abstract
Polycyclic aromatic hydrocarbons and polycyclic aromatic nitrogen heterocycles are thought to be widespread throughout the universe, because these classes of molecules are probably responsible for the unidentified infrared bands, a set of emission features seen in numerous Galactic and extragalactic sources. Despite their expected ubiquity, astronomical identification of specific aromatic molecules has proven elusive. We present the discovery of benzonitrile (c-C6H5CN), one of the simplest nitrogen-bearing aromatic molecules, in the interstellar medium. We observed hyperfine-resolved transitions of benzonitrile in emission from the molecular cloud TMC-1. Simple aromatic molecules such as benzonitrile may be precursors for polycyclic aromatic hydrocarbon formation, providing a chemical link to the carriers of the unidentified infrared bands.
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Shingledecker CN, Le Gal R, Herbst E. A new model of the chemistry of ionizing radiation in solids: CIRIS. Phys Chem Chem Phys 2017; 19:11043-11056. [DOI: 10.1039/c7cp01472d] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We simulate irradiated O2 ice, both reproducing measured ozone abundances and predicting the ice thickness of a previous experiment.
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Affiliation(s)
| | - Romane Le Gal
- Department of Chemistry
- University of Virginia
- Charlottesville
- USA
- Department of Astronomy
| | - Eric Herbst
- Department of Chemistry
- University of Virginia
- Charlottesville
- USA
- Department of Astronomy
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Marchione D, McCoustra MRS. Electrons, excitons and hydrogen bonding: electron-promoted desorption from molecular ice surfaces. Phys Chem Chem Phys 2016; 18:29747-29755. [DOI: 10.1039/c6cp05814k] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Desorption of benzene from methanol and diethyl ether ices during irradiation with 250 eV electrons is reported and compared with our previous work on benzene/water ices to highlight the role of hydrogen bonding in excitation transport.
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