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Góbi S, Keresztes B, Schneiker A, Tarczay G. UV photolysis of thiourea and its N-methylated derivative in cryogenic matrices. Phys Chem Chem Phys 2024; 26:9963-9974. [PMID: 38477114 DOI: 10.1039/d4cp00016a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2024]
Abstract
Exploration of the photolytic dynamics of sulfurous compounds is essential, eventually contributing not only to our comprehension of their fundamental organic chemistry but also shedding light on astrophysical implications. This study aims to investigate two astrochemically relevant sulfur-containing molecules, namely, thiourea (TU) and its N-methylated counterpart, N-methyl thiourea (NMTU), in cryogenic matrices. These molecules were deposited both in solid Ar and in a quantum host, specifically in solid para-H2 matrices, with the latter exhibiting unique properties. The deposited matrices were exposed to a series of UV laser irradiation at various wavelengths to investigate the decomposition paths of TU and NMTU. As a result of the UV photolysis, a plethora of degradation products could be observed in every case. Based on the presence of these product molecules, some considerations can be made regarding the decomposition mechanism of the parent molecules. The use of different matrices allowed for assessing their influence on the decay mechanism, while applying tunable laser light provided insights into the wavelength dependency of the processes.
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Affiliation(s)
- Sándor Góbi
- Laboratory of Molecular Spectroscopy, Institute of Chemistry, ELTE Eötvös Loránd University, PO Box 32, Budapest H-1518, Hungary.
- MTA-ELTE Lendület Laboratory Astrochemistry Research Group, Institute of Chemistry, ELTE Eötvös Loránd University, PO Box 32, Budapest H-1518, Hungary
| | - Barbara Keresztes
- Laboratory of Molecular Spectroscopy, Institute of Chemistry, ELTE Eötvös Loránd University, PO Box 32, Budapest H-1518, Hungary.
- Hevesy György PhD School of Chemistry, Institute of Chemistry, ELTE Eötvös Loránd University, PO Box 32, Budapest H-1518, Hungary
| | - Anita Schneiker
- Laboratory of Molecular Spectroscopy, Institute of Chemistry, ELTE Eötvös Loránd University, PO Box 32, Budapest H-1518, Hungary.
- Hevesy György PhD School of Chemistry, Institute of Chemistry, ELTE Eötvös Loránd University, PO Box 32, Budapest H-1518, Hungary
| | - György Tarczay
- Laboratory of Molecular Spectroscopy, Institute of Chemistry, ELTE Eötvös Loránd University, PO Box 32, Budapest H-1518, Hungary.
- MTA-ELTE Lendület Laboratory Astrochemistry Research Group, Institute of Chemistry, ELTE Eötvös Loránd University, PO Box 32, Budapest H-1518, Hungary
- Centre for Astrophysics and Space Science, ELTE Eötvös Loránd University, PO Box 32, Budapest H-1518, Hungary
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Góbi S, Keresztes B, Schneiker A, Ragupathy G, Tarczay G. Energetic processing of thioacetamide in cryogenic matrices. J Chem Phys 2024; 160:024310. [PMID: 38214387 DOI: 10.1063/5.0177587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 12/11/2023] [Indexed: 01/13/2024] Open
Abstract
There is an ongoing debate on the apparent depletion of sulfur in the interstellar medium (ISM) compared to its universal abundance; therefore, the investigation of sulfurous compounds at low temperatures is of utmost importance. This work aims to study thioacetamide, H3C-C(=S)-NH2, in low-temperature inert Ar and para-H2 matrices by IR spectroscopy. The samples have been exposed to various sources of irradiation, such as Lyman-α or laser UV photons as well as energetic electrons. Using different host materials enabled assessing the matrix's impact on precursor decomposition. The response of the molecule to different types of irradiation has also been evaluated. The existence of three main decomposition channels were deduced: formation of (i) CH3, CH4, and HNCS; (ii) H2S and H2C=C=NH; and (iii) NH3 and H2C=C=S. The H3C-CN and H3C-NC isomers of H2C=C=NH could also be identified. Secondary products such as HNC and HCN were also detected in the quantum solid para-H2 in contrast to the more rigid Ar matrix. The listed decomposition products have been observed in the ISM, with the exception of H2C=C=NH and H3C-NC. The results point to the potential sensitivity of the precursor molecule to energetic radiation in space environments. Finally, the findings of this work will serve as a foundation for future irradiation experiments using the astrochemically more relevant pure thioacetamide ice.
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Affiliation(s)
- Sándor Góbi
- MTA-ELTE Lendület Laboratory Astrochemistry Research Group, Institute of Chemistry, ELTE Eötvös Loránd University, P.O. Box 32, H-1518 Budapest, Hungary
- Laboratory of Molecular Spectroscopy, Institute of Chemistry, ELTE Eötvös Loránd University, P.O. Box 32, H-1518 Budapest, Hungary
| | - Barbara Keresztes
- Laboratory of Molecular Spectroscopy, Institute of Chemistry, ELTE Eötvös Loránd University, P.O. Box 32, H-1518 Budapest, Hungary
- Hevesy György PhD School of Chemistry, Institute of Chemistry, ELTE Eötvös Loránd University, P.O. Box 32, H-1518 Budapest, Hungary
| | - Anita Schneiker
- Laboratory of Molecular Spectroscopy, Institute of Chemistry, ELTE Eötvös Loránd University, P.O. Box 32, H-1518 Budapest, Hungary
- Hevesy György PhD School of Chemistry, Institute of Chemistry, ELTE Eötvös Loránd University, P.O. Box 32, H-1518 Budapest, Hungary
| | - Gopi Ragupathy
- MTA-ELTE Lendület Laboratory Astrochemistry Research Group, Institute of Chemistry, ELTE Eötvös Loránd University, P.O. Box 32, H-1518 Budapest, Hungary
| | - György Tarczay
- MTA-ELTE Lendület Laboratory Astrochemistry Research Group, Institute of Chemistry, ELTE Eötvös Loránd University, P.O. Box 32, H-1518 Budapest, Hungary
- Laboratory of Molecular Spectroscopy, Institute of Chemistry, ELTE Eötvös Loránd University, P.O. Box 32, H-1518 Budapest, Hungary
- Centre for Astrophysics and Space Science, ELTE Eötvös Loránd University, P.O. Box 32, H-1518 Budapest, Hungary
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Jelenfi DP, Schneiker A, Tajti A, Magyarfalvi G, Tarczay G. Polyaromatic hydrocarbons with an imperfect aromatic system as catalysts of interstellar H 2 formation. Mol Phys 2022. [DOI: 10.1080/00268976.2022.2142168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Dávid P. Jelenfi
- Hevesy György PhD School of Chemistry, ELTE Eötvös Loránd University, Budapest, Hungary
- Institute of Chemistry, Laboratory of Theoretical Chemistry, ELTE – Eötvös Loránd University, Budapest, Hungary
| | - Anita Schneiker
- Hevesy György PhD School of Chemistry, ELTE Eötvös Loránd University, Budapest, Hungary
- Institute of Chemistry, Laboratory of Molecular Spectroscopy, ELTE – Eötvös Loránd University, Budapest, Hungary
| | - Attila Tajti
- Institute of Chemistry, Laboratory of Theoretical Chemistry, ELTE – Eötvös Loránd University, Budapest, Hungary
| | - Gábor Magyarfalvi
- Institute of Chemistry, Laboratory of Molecular Spectroscopy, ELTE – Eötvös Loránd University, Budapest, Hungary
| | - György Tarczay
- Institute of Chemistry, Laboratory of Molecular Spectroscopy, ELTE – Eötvös Loránd University, Budapest, Hungary
- MTA-ELTE Lendület Laboratory Astrochemistry Research Group, Budapest, Hungary
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Schneiker A, Ragupathy G, Bazsó G, Tarczay G. Potential Catalytic Role of Small Heterocycles in Interstellar H 2 Formation: A Laboratory Astrochemistry Study on Furan and Its Hydrogenated Forms. J Phys Chem A 2022; 126:2832-2844. [PMID: 35467858 DOI: 10.1021/acs.jpca.2c00306] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
It is now well-accepted in astrochemistry that the formation of interstellar H2 is taking place on the surface of interstellar grains. It has also been suggested a long time ago that polyaromatic hydrocarbons (PAHs) can catalyze this process by subsequent H atom addition and H abstraction reactions. Recent quantum chemical computations suggested that small heterocycles can be better catalysts than PAHs. In this study, the reaction of H atoms with furan, 2,3- and 2,5-dihydrofurans, and tetrahydrofuran were studied in solid para-H2 at 3.1 K. The reactions were followed by Fourier transform infrared (FTIR) spectroscopy. By the analysis of spectra, 2-hydrofuran-3-yl, 3-hydrofuran-2-yl, 2,3,4-trihydrofuran-5-yl, and 2,3,5-trihydrofuran-4-yl radicals were identified among the products. The experiments revealed that all the possible H atom addition and H abstraction cycles connecting furan and tetrahydrofuran proceed effectively in both directions at a low temperature. This indicates the possible important role of small heterocycles in interstellar H2 formation. Furthermore, it also indicates that, in the case of H atom excess, a quasi-equilibrium exists between the c-C4HxO (x = 4-8) species, and the ratios of these species in an astrophysical object are determined by the rate of the different H atom addition and H abstraction reaction steps.
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Affiliation(s)
- Anita Schneiker
- George Hevesy Doctoral School, ELTE Eötvös Loránd University, H-1518 Budapest, Hungary.,MTA-ELTE Lendület Laboratory Astrochemistry Research Group, Institute of Chemistry, ELTE Eötvös Loránd University, P.O. Box 32, H-1518 Budapest 112, Hungary
| | - Gopi Ragupathy
- MTA-ELTE Lendület Laboratory Astrochemistry Research Group, Institute of Chemistry, ELTE Eötvös Loránd University, P.O. Box 32, H-1518 Budapest 112, Hungary
| | - Gábor Bazsó
- Wigner Research Centre for Physics, P.O. Box 49, H-1525 Budapest, Hungary
| | - György Tarczay
- MTA-ELTE Lendület Laboratory Astrochemistry Research Group, Institute of Chemistry, ELTE Eötvös Loránd University, P.O. Box 32, H-1518 Budapest 112, Hungary.,Laboratory of Molecular Spectroscopy, Institute of Chemistry, ELTE Eötvös Loránd University, P.O. Box 32, H-1518 Budapest 112, Hungary.,Centre for Astrophysics and Space Science, ELTE Eötvös Loránd University, P.O. Box 32, H-1518 Budapest 112, Hungary
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Schneiker A, Góbi S, Joshi PR, Bazsó G, Lee YP, Tarczay G. Non-energetic, Low-Temperature Formation of C α-Glycyl Radical, a Potential Interstellar Precursor of Natural Amino Acids. J Phys Chem Lett 2021; 12:6744-6751. [PMID: 34264091 DOI: 10.1021/acs.jpclett.1c01306] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The reaction of H atoms with glycine was investigated at 3.1 K in para-H2, a quantum-solid host. The reaction was followed by IR spectroscopy, with the spectral analysis aided by quantum chemical computations. Comparison of the experimental IR spectrum with computed anharmonic frequencies and intensities proved that, regardless of the reactant glycine conformation, Cα-glycyl radical is formed in an H-atom-abstraction process with great selectivity. The product of the second H-atom abstraction, iminoacetic acid, was also observed in a smaller amount. The Cα-glycyl radical is sensitive to UV light and decomposes to iminoacetic acid and H atom upon 280 nm radiation. Since the reactive radical center is located on the Cα-atom, it is suggested that natural α-amino acids can be formed from glycine via the Cα-glycyl radical by non-energetic mechanisms in the solid phase of the interstellar medium.
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Affiliation(s)
- Anita Schneiker
- MTA-ELTE Lendület Laboratory Astrochemistry Research Group, Institute of Chemistry, ELTE Eötvös Loránd University, H-1518 Budapest, Hungary
- Laboratory of Molecular Spectroscopy, Institute of Chemistry, ELTE Eötvös Loránd University, H-1518 Budapest, Hungary
| | - Sándor Góbi
- MTA-ELTE Lendület Laboratory Astrochemistry Research Group, Institute of Chemistry, ELTE Eötvös Loránd University, H-1518 Budapest, Hungary
| | - Prasad Ramesh Joshi
- Department of Applied Chemistry and Institute of Molecular Science, National Yang Ming Chiao Tung University, Hsinchu 300093, Taiwan
| | - Gábor Bazsó
- Wigner Research Centre for Physics, P. O. Box 49, H-1525 Budapest, Hungary
| | - Yuan-Pern Lee
- Department of Applied Chemistry and Institute of Molecular Science, National Yang Ming Chiao Tung University, Hsinchu 300093, Taiwan
- Center for Emergent Functional Matter Science, National Chiao Tung University, Hsinchu 300093, Taiwan
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106319, Taiwan
| | - György Tarczay
- MTA-ELTE Lendület Laboratory Astrochemistry Research Group, Institute of Chemistry, ELTE Eötvös Loránd University, H-1518 Budapest, Hungary
- Laboratory of Molecular Spectroscopy, Institute of Chemistry, ELTE Eötvös Loránd University, H-1518 Budapest, Hungary
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Schneiker A, Csonka IP, Tarczay G. Hydrogenation and dehydrogenation reactions of the phenalenyl radical/1H-phenalene system at low temperatures. Chem Phys Lett 2020. [DOI: 10.1016/j.cplett.2020.137183] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Kieninger M, Zech N, Mulzer Y, Bele S, Seemann M, Künzig H, Schneiker A, Gruber M. [Optimization of blood gas analysis in intensive care units : Reduction of preanalytical errors and improvement of workflow]. Anaesthesist 2015; 64:365-72. [PMID: 25896414 DOI: 10.1007/s00101-015-0024-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 03/09/2015] [Accepted: 03/15/2015] [Indexed: 11/26/2022]
Abstract
BACKGROUND Point of care testing with blood gas analysis (BGA) is an important factor for intensive care medicine. Continuous efforts to optimize workflow, improve safety for the staff and avoid preanalytical mistakes are important and should reflect quality management standards. AIM In a prospective observational study it was investigated whether the implementation of a new system for BGA using labeled syringes and automated processing of the specimens leads to improvements compared to the previously used procedure. MATERIAL AND METHODS In a 4-week test period the time until receiving the final results of the BGA with the standard method used in the clinical routine (control group) was compared to the results in a second 4-week test period using the new labeled syringes and automated processing of the specimens (intervention group). In addition, preanalytical mistakes with both systems were checked during routine daily use. Finally, it was investigated whether a delay of 10 min between taking and analyzing the blood samples alters the results of the BGA. RESULTS Preanalytical errors were frequently observed in the control group where non-deaerated samples were recorded in 87.3 % but in the intervention group almost all samples (98.9 %) were correctly deaerated. Insufficient homogenization due to omission of manual pivoting was seen in 83.2 % in the control group and in 89.9 % in the intervention group; however, in the intervention group the samples were homogenized automatically during the further analytical process. Although a survey among the staff revealed a high acceptance of the new system and a subjective improvement of workflow, a measurable gain in time after conversion to the new procedure could not be seen. The mean time needed for a complete analysis process until receiving the final results was 244 s in the intervention group and 201 s in the control group. A 10-min delay between taking and analyzing the blood samples led to a significant and clinically relevant elevation of the values for partial pressure of oxygen (pO2) in both groups compared to the results when analyzing the samples immediately (118.4 vs. 148.6 mmHg in the control group and 115.3 vs. 123.7 mmHg in the intervention group). When using standard syringes the partial pressure of carbon dioxide (pCO2) was significantly lower (40.5 vs. 38.3 mmHg) whereas no alterations were seen when using the labeled syringes. CONCLUSION The implementation of a new BGA system with labeled syringes and automated processing of the specimens was possible without any difficulties under daily clinical routine conditions in this 10-bed intensive care unit (ICU). A gain of time could not be measured but a reduction in preanalytical errors using the labeled syringes with automated processing was found. Delayed analysis of blood samples can lead to significant changes in pO2 and pCO2 depending on the type of syringe used.
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Affiliation(s)
- M Kieninger
- Klinik für Anästhesiologie, Universitätsklinikum Regensburg, Franz-Josef-Strauß-Allee 11, 93053, Regensburg, Deutschland,
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