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Worzakowska M, Sztanke K, Sztanke M. Studies on the Thermal Decomposition Course of Nitrogen-Rich Heterocyclic Esters as Potential Drug Candidates and Evaluation of Their Thermal Stability and Properties. Int J Mol Sci 2024; 25:4768. [PMID: 38731989 PMCID: PMC11084317 DOI: 10.3390/ijms25094768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 04/22/2024] [Accepted: 04/25/2024] [Indexed: 05/13/2024] Open
Abstract
Drug candidates must undergo thermal evaluation as early as possible in the preclinical phase of drug development because undesirable changes in their structure and physicochemical properties may result in decreased pharmacological activity or enhanced toxicity. Hence, the detailed evaluation of nitrogen-rich heterocyclic esters as potential drug candidates, i.e., imidazolidinoannelated triazinylformic acid ethyl esters 1-3 (where R1 = 4-CH3 or 4-OCH3 or 4-Cl, and R2 = -COOC2H5) and imidazolidinoannelated triazinylacetic acid methyl esters 4-6 (where R1 = 4-CH3 or 4-OCH3 or 4-Cl, and R2 = -CH2COOCH3)-in terms of their melting points, melting enthalpy values, thermal stabilities, pyrolysis, and oxidative decomposition course-has been carried out, using the simultaneous thermal analysis methods (TG/DTG/DSC) coupled with spectroscopic techniques (FTIR and QMS). It was found that the melting process (documented as one sharp peak related to the solid-liquid phase transition) of the investigated esters proceeded without their thermal decomposition. It was confirmed that the melting points of the tested compounds increased in relation to R1 and R2 as follows: 2 (R1 = 4-OCH3; R2 = -COOC2H5) < 6 (R1 = 4-Cl; R2 = -CH2COOCH3) < 5 (R1 = 4-OCH3; R2 = -CH2COOCH3) < 3 (R1 = 4-Cl; R2 = -COOC2H5) < 1 (R1 = 4-CH3; R2 = -COOC2H5) < 4 (R1 = 4-CH3; R2 = -CH2COOCH3). All polynitrogenated heterocyclic esters proved to be thermally stable up to 250 °C in inert and oxidising conditions, although 1-3 were characterised by higher thermal stability compared to 4-6. The results confirmed that both the pyrolysis and the oxidative decomposition of heterocyclic ethyl formates/methyl acetates with para-substitutions at the phenyl moiety proceed according to the radical mechanism. In inert conditions, the pyrolysis process of the studied molecules occurred with the homolytic breaking of the C-C, C-N, and C-O bonds. This led to the emission of alcohol (ethanol in the case of 1-3 or methanol in the case of 4-6), NH3, HCN, HNCO, aldehydes, CO2, CH4, HCl, aromatics, and H2O. In turn, in the presence of air, cleavage of the C-C, C-N, and C-O bonds connected with some oxidation and combustion processes took place. This led to the emission of the corresponding alcohol depending on the analysed class of heterocyclic esters, NH3, HCN, HNCO, aldehydes, N2, NO/NO2, CO, CO2, HCl, aromatics, and H2O. Additionally, after some biological tests, it was proven that all nitrogen-rich heterocyclic esters-as potential drug candidates-are safe for erythrocytes, and some of them are able to protect red blood cells from oxidative stress-induced damage.
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Affiliation(s)
- Marta Worzakowska
- Department of Polymer Chemistry, Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Sklodowska University in Lublin, 33 Gliniana Street, 20-614 Lublin, Poland;
| | - Krzysztof Sztanke
- Laboratory of Bioorganic Compounds Synthesis and Analysis, Medical University of Lublin, 4A Chodźki Street, 20-093 Lublin, Poland;
| | - Małgorzata Sztanke
- Department of Medical Chemistry, Medical University of Lublin, 4A Chodźki Street, 20-093 Lublin, Poland
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2
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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] [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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3
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Sałdyka M, Mielke Z. UV Laser-Induced Photodecomposition of Matrix-Isolated Salicylhydroxamic Acid: Identification of New Isocyanate Complexes. Molecules 2024; 29:862. [PMID: 38398614 PMCID: PMC10892988 DOI: 10.3390/molecules29040862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 02/05/2024] [Accepted: 02/10/2024] [Indexed: 02/25/2024] Open
Abstract
Photochemical reactions of salicylhydroxamic acid were induced using tunable UV laser radiation followed by FTIR spectroscopy. Four pairs of co-products were experimentally found to appear in the photolysis: C6H4(OH)NCO⋯H2O (1), C6H4(OH)C(O)N⋯H2O (2), C6H4(OH)2⋯HNCO (3), and C6H4(OH)NHOH⋯CO (4). The comparison of the theoretical spectra with the experimental ones allowed us to determine the structures of the complexes formed in the matrices. The mechanisms of the reaction channels leading to the formation of the photoproducts were proposed. It was concluded that the first step in the formation of the complexes (1), (2), and (3) was the scission of the N-O bond, whereas the creation of complex (4) was due to cleavage of the C-N bond.
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Affiliation(s)
- Magdalena Sałdyka
- Faculty of Chemistry, University of Wroclaw, F. Joliot-Curie 14, 50-383 Wrocław, Poland
| | - Zofia Mielke
- Faculty of Chemistry, University of Wroclaw, F. Joliot-Curie 14, 50-383 Wrocław, Poland
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4
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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] [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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Moore B, Mahoney K, Zeng MF, Djuricanin P, Momose T. Ultraviolet Photodissociation of Proteinogenic Amino Acids. J Am Chem Soc 2023; 145:11045-11055. [PMID: 37167534 DOI: 10.1021/jacs.3c00124] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The ultraviolet photochemistry of the amino acids glycine, leucine, proline, and serine in their neutral forms was investigated using parahydrogen matrix-isolation spectroscopy. Irradiation by 213 nm light destroys the chirality of all three chiral amino acids as a result of the α-carbonyl C-C bond cleavage and hydrocarboxyl (HOCO) radical production. The temporal behavior of the Fourier-transform infrared spectra revealed that HOCO radicals rapidly reach a steady state, which occurs predominantly due to photodissociation of HOCO into CO + OH or CO2 + H. In glycine and leucine, the amine radicals generated by the α-carbonyl C-C bond cleavage rapidly undergo hydrogen elimination to yield methanimine and 3-methylbutane-1-imine, respectively. Breaking of the α-carbonyl C-C bond in proline appeared to yield 1-pyrroline, although due to its weak absorption it remains unconfirmed. In serine, additional products were formaldehyde and E/Z ethanimine. The present study shows that the direct production of HOCO previously observed in α-alanine generalizes to other amino acids of varying structure. It also revealed a tendency for amino acid photolysis to form imines rather than amine radicals. HOCO should be useful in the search for amino acids in interstellar space, particularly in combination with simple imine molecules.
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Affiliation(s)
- Brendan Moore
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Kyle Mahoney
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Mei Fei Zeng
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Pavle Djuricanin
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Takamasa Momose
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
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6
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Weber I, Tsuge M, Sundararajan P, Baba M, Sakurai H, Lee YP. Infrared and Laser-Induced Fluorescence Spectra of Sumanene Isolated in Solid para-Hydrogen. J Phys Chem A 2022; 126:5283-5293. [PMID: 35921614 DOI: 10.1021/acs.jpca.2c02906] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The para-hydrogen (p-H2) matrix-isolation technique has been scarcely used to record electronic absorption and emission spectra. It is expected that its small matrix shifts due to diminished molecular interactions and the softness of the lattice might be advantageous to help identify the carriers of the diffuse interstellar bands. In this article, we present infrared, fluorescence excitation, and dispersed fluorescence spectra of sumanene (C21H12), a bowl-shaped polycyclic aromatic hydrocarbon and a fragment of C60, isolated in solid p-H2. The recorded vibrational wavenumbers from infrared and dispersed fluorescence agree with the scaled harmonic vibrational wavenumbers calculated with the B3PW91/6-311++G(2d,2p) and B3LYP/6-311++G(2d,2p) methods. The recorded fluorescence excitation spectra are consistent with the spectra of jet-cooled gas-phase C21H12 reported previously by Kunishige et al. We found a rather small matrix shift of 55 cm-1 for the S1-S0 electronic transition origin located at 27 888 cm-1. Vibrational wavenumbers associated with the S1 state of C21H12 inferred from the experimental spectrum can be assigned mostly to fundamental normal modes; they are in satisfactory agreement with scaled harmonic vibrational wavenumbers calculated at the TD-B3PW91/6-311++G(2d,2p) level of theory. Significantly more vibrational modes of the S1 state were identified as compared with those in the reported gas-phase work. The potential of p-H2 matrix-isolation spectroscopy to provide electronic excitation spectra suitable for comparison to astronomical observations is discussed by comparing the spectra of C21H12 isolated in solid p-H2 and in solid Ne, a matrix host commonly employed in astrochemistry.
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Affiliation(s)
- Isabelle Weber
- Department of Applied Chemistry and Institute of Molecular Science, National Yang Ming Chiao Tung University, Hsinchu 3000093, Taiwan
| | - Masashi Tsuge
- Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819, Japan
| | - Pavithraa Sundararajan
- Department of Applied Chemistry and Institute of Molecular Science, National Yang Ming Chiao Tung University, Hsinchu 3000093, Taiwan
| | - Masaaki Baba
- Division of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.,Molecular Photoscience Research Center, Kobe University, Kobe 657-8501, Japan
| | - Hidehiro Sakurai
- Division of Applied Chemistry, Graduate School of Engineering and Innovative Catalysis Science Division, Institute for Open and Transdisciplinary Research Initiatives (ICS-OTRI), Osaka University, Osaka 565-0871, Japan
| | - Yuan-Pern Lee
- Department of Applied Chemistry and Institute of Molecular Science, National Yang Ming Chiao Tung University, Hsinchu 3000093, Taiwan.,Center for Emergent Functional Matter Science, National Yang Ming Chiao Tung University, Hsinchu 300093, Taiwan
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7
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Haupa KA, Joshi PR, Lee Y. Hydrogen‐atom tunneling reactions in solid
para
‐hydrogen and their applications to astrochemistry. J CHIN CHEM SOC-TAIP 2022. [DOI: 10.1002/jccs.202200210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Karolina Anna Haupa
- Department of Applied Chemistry and Institute of Molecular Science National Yang Ming Chiao Tung University Hsinchu Taiwan
- Institute of Physical Chemistry Karlsruhe Institute of Technology Karlsruhe Germany
| | - Prasad Ramesh Joshi
- Department of Applied Chemistry and Institute of Molecular Science National Yang Ming Chiao Tung University Hsinchu Taiwan
| | - Yuan‐Pern Lee
- Department of Applied Chemistry and Institute of Molecular Science National Yang Ming Chiao Tung University Hsinchu Taiwan
- Center for Emergent Functional Matter Science National Yang Ming Chiao Tung University Hsinchu Taiwan
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8
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Tsai SY, Haupa KA, Lee YP. Hydrogen-Atom-Assisted Uphill Isomerization of N-Methylformamide in Darkness. J Am Chem Soc 2022; 144:12339-12346. [PMID: 35771208 DOI: 10.1021/jacs.2c03714] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
N-Methylformamide, HC(O)NH(CH3), is the smallest amide detected in the interstellar medium that can exist as cis and trans isomers. We performed reactions of H atoms with trans-NMF in solid para-hydrogen at 3.3 K and found that the cis-NMF isomer, which has higher energy, increased continuously in darkness, demonstrating a previously overlooked and seemingly unlikely isomerization of prebiotic molecules through H-atom tunneling reactions in the absence of light. Infrared spectra of radical intermediates trans-•C(O)NH(CH3) and trans-HC(O)NH(•CH2) were identified. Further H addition and H abstraction enhanced the formation of CH3NCO, HNCO, and CH2NH in the H-rich experiments. These results indicate that, unlike the dual cycle of H-abstraction and H-addition channels chemically linking formamide and HNCO, the H addition to CH3NCO produced only cis-radicals that led to cis-NMF. Furthermore, H-atom-induced fragmentation by breaking the C-C bond provides links between NMF and HCNO/CH2NH. These endothermic isomerization/decomposition reactions become possible through the coupling with H + H → H2.
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Affiliation(s)
- Shih-Yi Tsai
- Department of Applied Chemistry and Institute of Molecular Science, National Yang Ming Chiao Tung University, Hsinchu 300093, Taiwan
| | - Karolina Anna Haupa
- Department of Applied Chemistry and Institute of Molecular Science, National Yang Ming Chiao Tung University, Hsinchu 300093, Taiwan.,Institute of Physical Chemistry, Karlsruhe Institute of Technology, Fritz-Haber Weg 2, Karlsruhe 76131, Germany
| | - 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 Yang Ming Chiao Tung University, Hsinchu 300093, Taiwan
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9
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Joshi PR, Lee YP. A chemical link between methylamine and methylene imine and implications for interstellar glycine formation. Commun Chem 2022; 5:62. [PMID: 36697745 PMCID: PMC9814145 DOI: 10.1038/s42004-022-00677-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 04/26/2022] [Indexed: 01/28/2023] Open
Abstract
Methylamine CH3NH2 is considered to be an important precursor of interstellar amino acid because hydrogen abstraction might lead to the aminomethyl radical •CH2NH2 that can react with •HOCO to form glycine, but direct evidence of the formation and spectral identification of •CH2NH2 remains unreported. We performed the reaction H + CH3NH2 in solid p-H2 at 3.2 K and observed IR spectra of •CH2NH2 and CH2NH upon irradiation and when the matrix was maintained in darkness. Previously unidentified IR spectrum of •CH2NH2 clearly indicates that •CH2NH2 can be formed from the reaction H + CH3NH2 in dark interstellar clouds. The observed dual-cycle mechanism containing two consecutive H-abstraction and two H-addition steps chemically connects CH3NH2 and CH2NH in interstellar media and explains their quasi-equilibrium. Experiments on CD3NH2 produced CD2HNH2, in addition to •CD2NH2 and CD2NH, confirming the occurrence of H addition to •CD2NH2.
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Affiliation(s)
- Prasad Ramesh Joshi
- grid.260539.b0000 0001 2059 7017Department of Applied Chemistry and Institute of Molecular Science, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
| | - Yuan-Pern Lee
- grid.260539.b0000 0001 2059 7017Department of Applied Chemistry and Institute of Molecular Science, National Yang Ming Chiao Tung University, Hsinchu, Taiwan ,grid.260539.b0000 0001 2059 7017Center for Emergent Functional Matter Science, National Yang Ming Chiao Tung University, Hsinchu, Taiwan ,grid.28665.3f0000 0001 2287 1366Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan
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10
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Mutunga FM, Olenyik KM, Strom AI, Anderson DT. Hydrogen atom quantum diffusion in solid parahydrogen: The H + N 2O → cis-HNNO → trans-HNNO reaction. J Chem Phys 2021; 154:014302. [PMID: 33412886 DOI: 10.1063/5.0028853] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The diffusion and reactivity of hydrogen atoms in solid parahydrogen at temperatures between 1.5 K and 4.3 K are investigated by high-resolution infrared spectroscopy. Hydrogen atoms are produced within solid parahydrogen as the by-products of the 193 nm in situ photolysis of N2O, which induces a two-step tunneling reaction, H + N2O → cis-HNNO → trans-HNNO. The second-order rate constant for the first step to form cis-HNNO is found to be inversely proportional to the N2O concentration after photolysis, indicating that the hydrogen atoms move through solid parahydrogen via quantum diffusion. This reaction only readily occurs at temperatures below 2.8 K, not due to an increased rate constant for the first reaction step at low temperatures but rather due to an increased selectivity to the reaction. The rate constant for the second step of the reaction mechanism involving unimolecular isomerization is shown to be independent of the N2O concentration as expected. The inverse concentration dependence of the rate constant for the reaction step that involves the hydrogen atom demonstrates clearly that quantum diffusion influences the reactivity of the hydrogen atoms in solid parahydrogen, which does not have an analogy in classical reaction kinetics.
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Affiliation(s)
| | - Kelly M Olenyik
- Department of Chemistry, University of Wyoming, Laramie, Wyoming 82071, USA
| | - Aaron I Strom
- Department of Chemistry, University of Wyoming, Laramie, Wyoming 82071, USA
| | - David T Anderson
- Department of Chemistry, University of Wyoming, Laramie, Wyoming 82071, USA
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12
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Amicangelo JC, Lee YP. Hydrogenation of pyrrole: Infrared spectra of the 2,3-dihydropyrrol-2-yl and 2,3-dihydropyrrol-3-yl radicals isolated in solid para-hydrogen. J Chem Phys 2020; 153:164302. [DOI: 10.1063/5.0024495] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Jay C. Amicangelo
- School of Science, Penn State Erie, The Behrend College, 4205 College Drive, Erie, Pennsylvania 16563, USA
| | - Yuan-Pern Lee
- Department of Applied Chemistry and Institute of Molecular Science, National 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
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13
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Tsuge M, Chen YH, Lee YP. Infrared Spectra of Isomers of Protonated Aniline in Solid para-Hydrogen. J Phys Chem A 2020; 124:2253-2263. [DOI: 10.1021/acs.jpca.0c00241] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Masashi Tsuge
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu 30010, Taiwan
- Institute of Low Temperature Sciences, Hokkaido University, Sapporo 060-0819, Japan
| | - Yu-Hsuan Chen
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu 30010, Taiwan
| | - Yuan-Pern Lee
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu 30010, Taiwan
- Center for Emergent Functional Matter Science, National Chiao Tung University, Hsinchu 30010, Taiwan
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
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14
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Sundararajan P, Tsuge M, Baba M, Sakurai H, Lee YP. Infrared spectrum of hydrogenated corannulene rim-HC 20H 10 isolated in solid para-hydrogen. J Chem Phys 2019; 151:044304. [PMID: 31370543 DOI: 10.1063/1.5111169] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Hydrogenated polycyclic aromatic hydrocarbons have been proposed to be carriers of the interstellar unidentified infrared (UIR) emission bands and the catalysts for formation of H2; spectral characterizations of these species are hence important. We report the infrared (IR) spectrum of mono-hydrogenated corannulene (HC20H10) in solid para-hydrogen (p-H2). In experiments of electron bombardment of a mixture of corannulene and p-H2 during deposition of a matrix at 3.2 K, two groups of spectral lines increased with time during maintenance of the matrix in darkness after deposition. Lines in one group were assigned to the most stable isomer of hydrogenated corannulene, rim-HC20H10, according to the expected chemistry and a comparison with scaled harmonic vibrational wavenumbers and IR intensities predicted with the B3PW91/6-311++G(2d,2p) method. The lines in the other group do not agree with predicted spectra of other HC20H10 isomers and remain unassigned. Alternative hydrogenation was achieved with H atoms produced photochemically in the infrared-induced reaction Cl + H2 (v = 1) → H + HCl in a Cl2/C20H10/p-H2 matrix. With this method, only lines attributable to rim-HC20H10 were observed, indicating that hydrogenation via a quantum-mechanical tunneling mechanism produces preferably the least-energy rim-HC20H10 regardless of similar barrier heights and widths for the formation of rim-HC20H10 and hub-HC20H10. The mechanisms of formation in both experiments are discussed. The bands near 3.3 and 3.4 µm of rim-HC20H10 agree with the UIR emission bands in position and relative intensity, but other bands do not match satisfactorily with the UIR bands.
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Affiliation(s)
- Pavithraa Sundararajan
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu 30010, Taiwan
| | - Masashi Tsuge
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu 30010, Taiwan
| | - Masaaki Baba
- Division of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Hidehiro Sakurai
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Osaka 565-0871, Japan
| | - Yuan-Pern Lee
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu 30010, Taiwan
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15
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Haupa KA, Tarczay G, Lee YP. Hydrogen Abstraction/Addition Tunneling Reactions Elucidate the Interstellar H2NCHO/HNCO Ratio and H2 Formation. J Am Chem Soc 2019; 141:11614-11620. [DOI: 10.1021/jacs.9b04491] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - György Tarczay
- HAS-ELTE Laboratory Astrochemistry Lendület Research Group, Pázmány P. S. 1/a, Budapest 1117, Hungary
- Laboratory of Molecular Spectroscopy, Institute of Chemistry, ELTE Eötvös Loránd University, Pázmány P. S. 1/a, Budapest 1117, Hungary
| | - Yuan-Pern Lee
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
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16
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Chakraborty A, Lee YP. Formation and infrared identification of protonated fluoranthene isomers 3-, 9-, and 10-C 16H 11+ in solid para-H 2. Phys Chem Chem Phys 2019; 21:1820-1829. [PMID: 30628616 DOI: 10.1039/c8cp05849k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Polycyclic aromatic hydrocarbons (PAH) and their derivatives are prospective carriers of unidentified infrared (UIR) emission features observed in interstellar media. Fluoranthene (C16H10) is a simple planar PAH with five- and six-membered rings; it can be considered as a fragment of C60, which, along with its cationic counterpart, has been identified in interstellar media. Protonated fluoranthene, C16H11+, was generated upon electron bombardment during deposition at 3.2 K of p-H2 containing fluoranthene in a small proportion. The intensities of infrared features of C16H11+ decreased after maintaining the matrix in darkness because of its neutralization with trapped electrons. According to the correlations in intensities upon neutralization and secondary photolysis, observed lines were classified into three groups which are assigned to isomers 3-C16H11+, 9-C16H11+, and 10-C16H11+. Experimental vibrational wavenumbers and relative IR intensities of the features agree with corresponding calculated values predicted for these three isomers of C16H11+ with the B3PW91/6-311++G(2d,2p) method. 3-C16H11+ and 9-C16H11+ are predicted to have the lowest energy (within 5 kJ mol-1), whereas 10- and 1-C16H11+ are lying above the global minimum 3-C16H11+ by ∼20 kJ mol-1. However, definitive identification of 1-C16H11+ could not be made as only the most intense line is tentatively assigned. Although the observed spectra of these isomers match unsatisfactorily with the UIR bands, they will facilitate the potential terrestrial and extraterrestrial identification of these species.
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Affiliation(s)
- Arghya Chakraborty
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, 1001 Ta-Hsueh Road, Hsinchu 30010, Taiwan.
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17
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Amicangelo JC, Lee YP. Infrared spectra of the 1,1-dimethylallyl and 1,2-dimethylallyl radicals isolated in solidpara-hydrogen. J Chem Phys 2018; 149:204304. [DOI: 10.1063/1.5054653] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Jay C. Amicangelo
- School of Science, Penn State Erie, The Behrend College, 4205 College Drive, Erie, Pennsylvania 16563, USA
| | - Yuan-Pern Lee
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu 30010, Taiwan
- Center for Emergent Functional Matter Science, National Chiao Tung University, Hsinchu 30010, Taiwan
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
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18
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Tsuge M, Lai CP, Lee YP. Infrared spectra of 3-hydroxy-(1H)-pyridinium cation and 3-hydroxy-(1H)-pyridinyl radical isolated in solid para-hydrogen. J Chem Phys 2018; 149:014306. [PMID: 29981551 DOI: 10.1063/1.5038363] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
As pyridine and its derivatives are regarded as building blocks of nitrogen-containing polycyclic aromatic hydrocarbons, spectral identifications of their protonated and hydrogenated species are important. The infrared (IR) absorption spectra of the 3-hydroxy-(1H)-pyridinium cation, 3-C5H4(OH)NH+, and the 3-hydroxy-(1H)-pyridinyl radical, 3-C5H4(OH)NH, produced on electron bombardment during deposition of a mixture of 3-hydroxypyridine, 3-C5H4(OH)N, and para-H2 to form a matrix at 3.2 K were recorded. Intense IR absorption lines of trans-3-C5H4(OH)NH+ at 3594.4, 3380.0, 1610.6, 1562.2, 1319.4, 1193.8, 1167.5, and 780.4 cm-1 and eleven weaker ones decreased in intensity after the matrix was maintained in darkness for 20 h, whereas lines of trans-3-C5H4(OH)NH at 3646.2, 3493.4, 3488.7, 1546.7, 1349.6, 1244.1, 1209.1, 1177.3, 979.8, and 685.2 cm-1 and nine weaker ones increased. The intensities of lines of trans-3-C5H4(OH)NH decreased upon irradiation at 520 nm and diminished nearly completely upon irradiation at 450 nm, whereas those of trans-3-C5H4(OH)NH+ remained unchanged upon irradiation at 370, 450, and 520 nm. Observed vibrational wavenumbers and relative intensities of these species agree satisfactorily with the scaled harmonic vibrational wavenumbers and IR intensities predicted with the B3LYP/aug-cc-pVTZ method. The observed 3-C5H4(OH)NH+ cation and 3-C5H4(OH)NH radical are predicted to be the most stable species among all possible isomers by quantum-chemical calculations.
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Affiliation(s)
- Masashi Tsuge
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu 30010, Taiwan
| | - Chia-Peng Lai
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu 30010, Taiwan
| | - Yuan-Pern Lee
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu 30010, Taiwan
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19
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Pinelo LF, Klotz ER, Wonderly WR, Paulson LO, Kettwich SC, Kubelka J, Anderson DT. Solid Parahydrogen Infrared Matrix Isolation and Computational Studies of Li n-(C 2H 4) m Complexes. J Phys Chem A 2018; 122:985-991. [PMID: 29301076 DOI: 10.1021/acs.jpca.7b11223] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Complexes of lithium atoms with ethylene have been identified as potential hydrogen storage materials. As a Li atom approaches an ethylene molecule, two distinct low-lying electronic states are established; one is the 2A1 electronic state (for C2v geometries) that is repulsive but supports a shallow van der Waals well and correlates with the Li 2s atomic state, and the second is a 2B2 electronic state that correlates with the Li 2p atomic orbital and is a strongly bound charge-transfer state. Only the 2B2 charge-transfer state would be advantageous for hydrogen storage because the strong electric dipole created in the Li-(C2H4) complex due to charge transfer can bind molecular hydrogen through dipole-induced dipole and dipole-quadrupole electrostatic interactions. Ab initio studies have produced conflicting results for which electronic state is the true ground state for the Li-(C2H4) complex. The most accurate ab initio calculations indicate that the 2A1 van der Waals state is slightly more stable. In contrast, argon matrix isolation experiments have clearly identified the Li-(C2H4) complex exists in the 2B2 state. Some have suggested that argon matrix effects shift the equilibrium toward the 2B2 state. We report the low-temperature synthesis and IR characterization of Lin-(C2H4)m (n = 1, m = 1 and 2) complexes in solid parahydrogen which are observed using the C═C stretching vibration of ethylene in the complex. These results show that under cryogenic hydrogen storage conditions the Li-(C2H4) complex is more stable in the 2B2 electronic state and thus constitutes a potential hydrogen storage material with desirable characteristics.
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Affiliation(s)
- Laura F Pinelo
- Department of Chemistry, University of Wyoming , Laramie, Wyoming 82071-3838, United States
| | - Elsbeth R Klotz
- Department of Chemistry, University of Wyoming , Laramie, Wyoming 82071-3838, United States
| | - William R Wonderly
- Department of Chemistry, University of Wyoming , Laramie, Wyoming 82071-3838, United States
| | - Leif O Paulson
- Department of Chemistry, University of Wyoming , Laramie, Wyoming 82071-3838, United States
| | - Sharon C Kettwich
- Department of Chemistry, University of Wyoming , Laramie, Wyoming 82071-3838, United States
| | - Jan Kubelka
- Department of Chemistry, University of Wyoming , Laramie, Wyoming 82071-3838, United States
| | - David T Anderson
- Department of Chemistry, University of Wyoming , Laramie, Wyoming 82071-3838, United States
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20
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Sałdyka M, Mielke Z. Photochemistry of Acetohydroxamic Acid in Solid Argon. FTIR and Theoretical Studies. J Phys Chem A 2018; 122:60-71. [PMID: 29216431 DOI: 10.1021/acs.jpca.7b09461] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The products formed during exposure of the CH3CONHOH/Ar (AHA/Ar) matrices to the full output of the Xe lamp and to 225 nm OPO radiation are studied. The irradiation promotes the isomerization, 1Z → 1E, and AHA photodissociation reactions. Four pairs of coproducts are experimentally found to appear in the photolysis, they form the complexes: CH3OH···HNCO (1), H2O···CH3NCO (2), H2O···CH3CNO (3) and CO···CH3NHOH (4). The structures of the complexes were optimized at the MP2 computational level with the 6-311++G(2d,2p) and aug-cc-pVTZ basis sets. Three local minima were predicted for the complex (1), two for the complexes (2) and (3) and four local minima were found for the complex (4). The comparison of the theoretical spectra with the experimental ones allowed us to determine the structures of the complexes formed in the matrix. The mechanisms of the reaction channels leading to formation of the four coproducts are proposed. It is concluded that the first step in formation of the (1), (2) and (3) complexes is the scission of the N-O bond whereas the creation of the complex (4) is due to the cleavage of the C-N bond.
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Affiliation(s)
- Magdalena Sałdyka
- Faculty of Chemistry, University of Wrocław , F. Joliot-Curie 14, 50-383 Wrocław, Poland
| | - Zofia Mielke
- Faculty of Chemistry, University of Wrocław , F. Joliot-Curie 14, 50-383 Wrocław, Poland
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21
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Das P, Tsuge M, Lee YP. Infrared absorption of t-HOCO+, H+(CO2)2, and HCO2− produced in electron bombardment of CO2 in solid para-H2. J Chem Phys 2016; 145:014306. [DOI: 10.1063/1.4954898] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Prasanta Das
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu 30010, Taiwan
| | - Masashi Tsuge
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu 30010, Taiwan
| | - Yuan-Pern Lee
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu 30010, Taiwan
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
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22
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Crespo-Otero R, Mardykov A, Sanchez-Garcia E, Sander W, Barbatti M. Photo-stability of peptide-bond aggregates: N-methylformamide dimers. Phys Chem Chem Phys 2015; 16:18877-87. [PMID: 25081138 DOI: 10.1039/c4cp02518k] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The formation of weakly-bound dimers of N-methylformamide (NMF) and the photochemistry of these dimers after irradiation at 248 nm were explored using matrix-isolation spectroscopy. Calculations were used to characterize the diverse isomers and assign their IR spectra; non-adiabatic dynamics was simulated to understand their photo-deactivation mechanism. The most stable dimers, and , were obtained by trans-trans aggregation (N-HO[double bond, length as m-dash]C interactions) and could be identified in the matrix. The main products formed after irradiation are the trans-cis dimers ( and ), also stabilized by N-HO[double bond, length as m-dash]C interactions. In contrast to the photochemistry of the monomers, no dissociative products were observed after 248 nm irradiation of the dimers. The absence of dissociative products can be explained by a proton-transfer mechanism in the excited state that is faster than the photo-dissociative mechanism. The fact that hydrogen bonding has such a significant effect on the photochemical stability of NMF has important implications to understand the stability of peptide-bonded systems to UV irradiation.
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Affiliation(s)
- Rachel Crespo-Otero
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilheim-Platz 1, 45470 Mülheim an der Ruhr, Germany.
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23
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Mutunga FM, Anderson DT. Infrared Spectroscopy and 193 nm Photochemistry of Methylamine Isolated in Solid Parahydrogen. J Phys Chem A 2014; 119:2420-8. [DOI: 10.1021/jp508476j] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Fredrick M. Mutunga
- Department of Chemistry, University of Wyoming, Laramie, Wyoming 82071, United States
| | - David T. Anderson
- Department of Chemistry, University of Wyoming, Laramie, Wyoming 82071, United States
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24
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Paulson LO, Mutunga FM, Follett SE, Anderson DT. Reactions of Atomic Hydrogen with Formic Acid and Carbon Monoxide in Solid Parahydrogen I: Anomalous Effect of Temperature. J Phys Chem A 2014; 118:7640-52. [DOI: 10.1021/jp502470j] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Leif O. Paulson
- Department of Chemistry, University of Wyoming, Laramie, Wyoming 82071, United States
| | - Fredrick M. Mutunga
- Department of Chemistry, University of Wyoming, Laramie, Wyoming 82071, United States
| | - Shelby E. Follett
- Department of Chemistry, University of Wyoming, Laramie, Wyoming 82071, United States
| | - David T. Anderson
- Department of Chemistry, University of Wyoming, Laramie, Wyoming 82071, United States
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25
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Eckert-Maksić M, Antol I, Vazdar M. Acetamide as the model of the peptide bond: Nonadiabatic photodynamical simulations in the gas phase and in the argon matrix. COMPUT THEOR CHEM 2014. [DOI: 10.1016/j.comptc.2014.02.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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26
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Das P, Lee YP. Bimolecular reaction of CH3 + CO in solid p-H2: Infrared absorption of acetyl radical (CH3CO) and CH3-CO complex. J Chem Phys 2014; 140:244303. [DOI: 10.1063/1.4883519] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Prasanta Das
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu 30010, Taiwan
| | - Yuan-Pern Lee
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu 30010, Taiwan
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
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27
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Chin W, Chevalier M, Thon R, Pollet R, Ceponkus J, Crépin C. Photochemistry of glycolaldehyde in cryogenic matrices. J Chem Phys 2014; 140:224319. [DOI: 10.1063/1.4881605] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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28
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Bahou M, Das P, Lee YF, Wu YJ, Lee YP. Infrared spectra of free radicals and protonated species produced in para-hydrogen matrices. Phys Chem Chem Phys 2014; 16:2200-10. [DOI: 10.1039/c3cp54184c] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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29
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Bahou M, Das P, Lee YF, Wu YJ, Lee YP. Infrared spectra of free radicals and protonated species produced in para-hydrogen matrices. Phys Chem Chem Phys 2014. [DOI: 10.10.1039/c3cp54184c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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30
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Golec B, Das P, Bahou M, Lee YP. Infrared Spectra of the 1-Pyridinium (C5H5NH+) Cation and Pyridinyl (C5H5NH and 4-C5H6N) Radicals Isolated in Solid para-Hydrogen. J Phys Chem A 2013; 117:13680-90. [DOI: 10.1021/jp407668z] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Barbara Golec
- Department
of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu 30010, Taiwan
| | - Prasanta Das
- Department
of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu 30010, Taiwan
| | - Mohammed Bahou
- Department
of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu 30010, Taiwan
| | - Yuan-Pern Lee
- Department
of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu 30010, Taiwan
- Institute
of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
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31
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Das P, Lee YP. Infrared absorption of 3-propenonyl (⋅CH2CHCO) radical generated upon photolysis of acryloyl chloride [CH2CHC(O)Cl] in solid para-H2. J Chem Phys 2013; 139:084320. [DOI: 10.1063/1.4818880] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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