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Sedmidubská B, Kočišek J. Interaction of low-energy electrons with radiosensitizers. Phys Chem Chem Phys 2024; 26:9112-9136. [PMID: 38376461 DOI: 10.1039/d3cp06003a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2024]
Abstract
We provide an experimentalist's perspective on the present state-of-the-art in the studies of low-energy electron interactions with common radiosensitizers, including compounds used in combined chemo-radiation therapy and their model systems. Low-energy electrons are important secondary species formed during the interaction of ionizing radiation with matter. Their role in the radiation chemistry of living organisms has become an important topic for more than 20 years. With the increasing number of works and reviews in the field, we would like to focus here on a very narrow area of compounds that have been shown to have radio-sensitizing properties on the one hand, and high reactivity towards low-energy electrons on the other hand. Gas phase experiments studying electron attachment to isolated molecules and environmental effects on reaction dynamics are reviewed for modified DNA components, nitroimidazoles, and organometallics. In the end, we provide a perspective on the future directions that may be important for transferring the fundamental knowledge about the processes induced by low-energy electrons into practice in the field of rational design of agents for concomitant chemo-radiation therapy.
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Affiliation(s)
- Barbora Sedmidubská
- J. Heyrovský Institute of Physical Chemistry of the CAS, Dolejškova 3, 182223 Prague, Czech Republic.
- Department of Nuclear Chemistry, Faculty of Nuclear Sciences and Physical Engineering, Břehová 7, 11519 Prague, Czech Republic
- Institut de Chimie Physique, UMR 8000 CNRS and Faculté des sciences d'Orsay, Université Paris Saclay, F-91405 Orsay Cedex, France
| | - Jaroslav Kočišek
- J. Heyrovský Institute of Physical Chemistry of the CAS, Dolejškova 3, 182223 Prague, Czech Republic.
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Skarmoutsos I, Mancera RL, Mossa S, Samios J. Local intermolecular structure, hydrogen bonding and related dynamics in the liquid cis/trans N-methylformamide mixture: A density functional theory based Born-Oppenheimer molecular dynamics study. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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3
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Biswas S, Mallik BS. Probing the vibrational dynamics of amide bands of N-methylformamide, N, N-dimethylacetamide, and N-methylacetamide in water. COMPUT THEOR CHEM 2020. [DOI: 10.1016/j.comptc.2020.113001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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4
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Biswas S, Mallik BS. Aqueous hydroxyl group as the vibrational probe to access the hydrophobicity of amide derivatives. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2019.112395] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Li Z, Ryszka M, Dawley MM, Carmichael I, Bravaya KB, Ptasińska S. Dipole-Supported Electronic Resonances Mediate Electron-Induced Amide Bond Cleavage. PHYSICAL REVIEW LETTERS 2019; 122:073002. [PMID: 30848645 DOI: 10.1103/physrevlett.122.073002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Revised: 10/11/2018] [Indexed: 05/28/2023]
Abstract
Dissociative electron attachment (DEA) plays a key role in radiation damage of biomolecules under high-energy radiation conditions. The initial step in DEA is often rationalized in terms of resonant electron capture into one of the metastable valence states of a molecule followed by its fragmentation. Our combined theoretical and experimental investigations indicate that the manifold of states responsible for electron capture in the DEA process can be dominated by core-excited (shake-up) dipole-supported resonances. Specifically, we present the results of experimental and computational studies of the gas-phase DEA to three prototypical peptide molecules, formamide, N-methylformamide (NMF), and N,N-dimethyl-formamide (DMF). In contrast to the case of electron capture by positively charged peptides in which amide bond rupture is rare compared to N─C_{α} bond cleavage, fragmentation of the amide bond was observed in each of these three molecules. The ion yield curves for ions resulting from this amide bond cleavage, such as NH_{2}^{-} for formamide, NHCH_{3}^{-} for NMF, and N(CH_{3})_{2}^{-} for DMF, showed a double-peak structure in the region between 5 and 8 eV. The peaks are assigned to Feshbach resonances including core-excited dipole-supported resonances populated upon electron attachment based on high-level electronic structure calculations. Moreover, the lower energy peak is attributed to formation of the core-excited resonance that correlates with the triplet state of the neutral molecule. The latter process highlights the role of optically spin-forbidden transitions promoted by electron impact in the DEA process.
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Affiliation(s)
- Zhou Li
- Radiation Laboratory, University of Notre Dame, Notre Dame, Indiana 46556, USA
- Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Michal Ryszka
- Radiation Laboratory, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - M Michele Dawley
- Radiation Laboratory, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Ian Carmichael
- Radiation Laboratory, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Ksenia B Bravaya
- Department of Chemistry, Boston University, Boston, Massachusetts 02215, USA
| | - Sylwia Ptasińska
- Radiation Laboratory, University of Notre Dame, Notre Dame, Indiana 46556, USA
- Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, USA
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Kopyra J, Kopyra KK, Abdoul-Carime H, Branowska D. Insights into the dehydrogenation of 2-thiouracil induced by slow electrons: Comparison of 2-thiouracil and 1-methyl-2-thiouracil. J Chem Phys 2018; 148:234301. [PMID: 29935521 DOI: 10.1063/1.5032162] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In the present contribution, we study dissociative electron attachment to 1-methyl-2-thiouracil that has been synthesized and purified prior to the measurements. We compare the results with those previously obtained from 2-thiouracil. The comparison of the yield of the dehydrogenated parent anion from both the compounds allows us to assign the site from which the H atom is expulsed and to predict the mechanism that is involved in the formation of the peaks within the ion yield curve. It appears that the dehydrogenation observed for 2-thiouracil arising from the vibrational Feshbach resonances (at 0.7 and 1.0 eV) and a π*/σ* transition (at 0.1 eV) involves the bond cleavage at the N1 site, while that at the N3 site operates via the π*/σ* transition and occurs in the energy range of 1.1-3.3 eV. Besides the loss of the H atom from 1-methyl-2-thiouracil, we observe a relatively strong signal due to the loss of an entire methyl group (not observed from methyl-substituted thymine and uracil) that is formed from the N1-CH3 bond cleavage and can mimic the N-glycosidic bond cleavage within the DNA macromolecule.
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Affiliation(s)
- Janina Kopyra
- Faculty of Sciences, Siedlce University, 3 Maja 54, 08-110 Siedlce, Poland
| | - Konstancja K Kopyra
- Faculty of Chemical and Process Engineering, Warsaw University of Technology, Waryńskiego 1, 00-645 Warsaw, Poland
| | - Hassan Abdoul-Carime
- Université de Lyon, F-69003 Lyon, France; Université Lyon 1, Villeurbanne, France; and CNRS/IN2P3, UMR5822, Institut de Physique Nucléaire de Lyon, Villeurbanne, France
| | - Danuta Branowska
- Faculty of Sciences, Siedlce University, 3 Maja 54, 08-110 Siedlce, Poland
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Liu W, Benson J, Dawson C, Strudwick A, Raju APA, Han Y, Li M, Papakonstantinou P. The effects of exfoliation, organic solvents and anodic activation on the catalytic hydrogen evolution reaction of tungsten disulfide. NANOSCALE 2017; 9:13515-13526. [PMID: 28869262 DOI: 10.1039/c7nr04790h] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The rational design of transition metal dichalcogenide electrocatalysts for efficiently catalyzing the hydrogen evolution reaction (HER) is believed to lead to the generation of a renewable energy carrier. To this end, our work has made three main contributions. At first, we have demonstrated that exfoliation via ionic liquid assisted grinding combined with gradient centrifugation is an efficient method to exfoliate bulk WS2 to nanosheets with a thickness of a few atomic layers and lateral size dimensions in the range of 100 nm to 2 nm. These WS2 nanosheets decorated with scattered nanodots exhibited highly enhanced catalytic performance for HER with an onset potential of -130 mV vs. RHE, an overpotential of 337 mV at 10 mA cm-2 and a Tafel slope of 80 mV dec-1 in 0.5 M H2SO4. Secondly, we found a strong aging effect on the electrocatalytic performance of WS2 stored in high boiling point organic solvents such as dimethylformamide (DMF). Importantly, the HER ability could be recovered by removing the organic (DMF) residues, which obstructed the electron transport, with acetone. Thirdly, we established that the HER performance of WS2 nanosheets/nanodots could be significantly enhanced by activating the electrode surface at a positive voltage for a very short time (60 s), decreasing the kinetic overpotential by more than 80 mV at 10 mA cm-2. The performance enhancement was found to arise primarily from the ability of a formed proton-intercalated amorphous tungsten trioxide (a-WO3) to provide additional active sites and favourably modify the immediate chemical environment of the WS2 catalyst, rendering it more favorable for local proton delivery and/or transport to the active edge site of WS2. Our results provide new insights into the effects of organic solvents and electrochemical activation on the catalytic performance of two-dimensional WS2 for HER.
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Affiliation(s)
- Wanglian Liu
- School of Engineering, Engineering Research Institute, Ulster University, Newtownabbey BT37 0QB, UK.
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Maeyama T, Shimamori T, Fujii A. Effects of Alkyl Groups on Excess-Electron Binding to Small-Sized Secondary Amide Clusters: A Combined Experimental and Computational Study. J Phys Chem A 2017; 121:4397-4403. [DOI: 10.1021/acs.jpca.6b10970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Toshihiko Maeyama
- Department of Chemistry,
Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578, Japan
| | - Takuto Shimamori
- Department of Chemistry,
Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578, Japan
| | - Asuka Fujii
- Department of Chemistry,
Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578, Japan
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Elpidoforou N, Skarmoutsos I, Kainourgiakis E, Raptis V, Samios J. Local structure and translational dynamics of NMF (N-methylformamide)–DMF (N,N-dimethylformamide) mixtures, via molecular dynamics simulation. J Mol Liq 2017. [DOI: 10.1016/j.molliq.2016.09.039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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10
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Nusrat Mafy N, Muhibur Rahman M, Mollah MYA, Susan MABH. Temperature Perturbation on Hydrogen Bonding in Aqueous Solutions at Different Amide Concentrations. ChemistrySelect 2016. [DOI: 10.1002/slct.201601136] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Noushaba Nusrat Mafy
- Department of Chemistry; University of Dhaka; Dhaka 1000 Bangladesh, (M.A.B.H. Susan
| | - M. Muhibur Rahman
- University Grants Commission of Bangladesh, 29/1 Agargaon; Sher-E-Banglanagar Dhaka 1207 Bangladesh
| | - M. Yousuf A. Mollah
- University Grants Commission of Bangladesh, 29/1 Agargaon; Sher-E-Banglanagar Dhaka 1207 Bangladesh
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11
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Dawley MM, Tanzer K, Carmichael I, Denifl S, Ptasińska S. Dissociative electron attachment to the gas-phase nucleobase hypoxanthine. J Chem Phys 2015; 142:215101. [DOI: 10.1063/1.4921388] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- M. Michele Dawley
- Radiation Laboratory, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Katrin Tanzer
- Institut für Ionenphysik und Angewandte Physik, and Center for Molecular Biosciences Innsbruck (CMBI), Leopold-Franzens Universität Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria
| | - Ian Carmichael
- Radiation Laboratory, University of Notre Dame, Notre Dame, Indiana 46556, USA
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Stephan Denifl
- Institut für Ionenphysik und Angewandte Physik, and Center for Molecular Biosciences Innsbruck (CMBI), Leopold-Franzens Universität Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria
| | - Sylwia Ptasińska
- Radiation Laboratory, University of Notre Dame, Notre Dame, Indiana 46556, USA
- Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, USA
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Wang Y, Guo M, Wei S, Yin S, Wang Y, Song Z, Hoffmann MR. Intermolecular hydrogen bonding of N-methylformamide in aqueous environment: A theoretical study. COMPUT THEOR CHEM 2014. [DOI: 10.1016/j.comptc.2014.09.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Hammami F, Chebaane A, Bahri M, Nasr S. Structural investigations of N-methylformamide-water mixtures at various concentrations. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2013; 36:129. [PMID: 24248215 DOI: 10.1140/epje/i2013-13129-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 09/09/2013] [Accepted: 10/18/2013] [Indexed: 06/02/2023]
Abstract
Structural investigations of N-methylformamide-water mixtures (NMF-water) are performed at room temperature and atmospheric pressure for two water molar fractions x w = 0.66 and x w = 0.75 . This paper extends our recent study on the equimolar system. H-bond networks are preferentially formed between NMF and water molecules. Among a large variety of DFT optimized models, X-ray scattering data shows that the local order of each mixture is better described by a tetramer where one NMF molecule is connected to three water molecules. No self-association is observed in the considered systems. The effect of hydration is compared to the temperature and pressure effects in some hydrogen-bonded liquids.
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Affiliation(s)
- Ferid Hammami
- Laboratoire Physico-Chimie des Matériaux, Département de Physique, Faculté des Sciences de Monastir, Université de Monastir, 5000, Monastir, Tunisie
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Fedorova IV, Safonova LP, Kiselev MG. Quantum chemical calculations of the structure of hydrogen-bonded sulfuric acid-dimethylformamide complexes. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2013. [DOI: 10.1134/s0036024413020325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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16
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Maeyama T, Yoshida K, Fujii A. Size-Dependent Metamorphosis of Electron Binding Motif in Cluster Anions of Primary Amide Molecules. J Phys Chem A 2012; 116:3771-80. [DOI: 10.1021/jp204621x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Toshihiko Maeyama
- Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578, Japan
| | - Keiji Yoshida
- Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578, Japan
| | - Asuka Fujii
- Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578, Japan
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17
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Song P, Zhu YH, Li YQ, Ding Y, Ma FC. Time-dependent Density Functional Theory Study on the Hydrogen-bonded Dimers Formed by Gauche-1PA and Trans-1PA. J CHIN CHEM SOC-TAIP 2012. [DOI: 10.1002/jccs.201100205] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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18
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Huck LA, Buriak JM. Toward a Mechanistic Understanding of Exciton-Mediated Hydrosilylation on Nanocrystalline Silicon. J Am Chem Soc 2011; 134:489-97. [DOI: 10.1021/ja208604r] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Lawrence A. Huck
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, and National Research Council Canada, National Institute for Nanotechnology, 11421 Saskatchewan Drive, Edmonton, Alberta T6G 2M9, Canada
| | - Jillian M. Buriak
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, and National Research Council Canada, National Institute for Nanotechnology, 11421 Saskatchewan Drive, Edmonton, Alberta T6G 2M9, Canada
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Ma M, Yang D. Time-Dependent Density Functional Theory Study on Excited-State Hydrogen Bonding Dynamics of Acetic Acid Hydrates. J CLUST SCI 2011. [DOI: 10.1007/s10876-011-0421-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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Lu JF, Wu YF, Yu ZY, Lin XJ. DFT study of ionization potentials and electron affinities of formamide and its methylation derivatives. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2011. [DOI: 10.1134/s003602441108019x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Kiselev MG, Safonova LP. Molecular dynamics simulation of Bu4N+ in dimethylformamide: Solvation-induced volume changes. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2011. [DOI: 10.1134/s0036024411060173] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Cordeiro JM, Soper AK. Investigation on the structure of liquid N-methylformamide–dimethylsulfoxide mixtures. Chem Phys 2011. [DOI: 10.1016/j.chemphys.2011.01.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Cordeiro JMM, Soper AK. Neutron Diffraction Study of Liquid N-Methylformamide Using EPSR Simulation. J Phys Chem B 2009; 113:6819-25. [DOI: 10.1021/jp902053y] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- João M. M. Cordeiro
- ISIS Facility, STFC Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxon, OX11 0QX, United Kingdon
| | - Alan K. Soper
- ISIS Facility, STFC Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxon, OX11 0QX, United Kingdon
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Panuszko A, Gojło E, Zielkiewicz J, Śmiechowski M, Krakowiak J, Stangret J. Hydration of Simple Amides. FTIR Spectra of HDO and Theoretical Studies. J Phys Chem B 2008; 112:2483-93. [PMID: 18247601 DOI: 10.1021/jp7099509] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Aneta Panuszko
- Department of Physical Chemistry, Chemical Faculty, Gdańsk University of Technology, Narutowicza 11/12, 80-952 Gdańsk, Poland
| | - Emilia Gojło
- Department of Physical Chemistry, Chemical Faculty, Gdańsk University of Technology, Narutowicza 11/12, 80-952 Gdańsk, Poland
| | - Jan Zielkiewicz
- Department of Physical Chemistry, Chemical Faculty, Gdańsk University of Technology, Narutowicza 11/12, 80-952 Gdańsk, Poland
| | - Maciej Śmiechowski
- Department of Physical Chemistry, Chemical Faculty, Gdańsk University of Technology, Narutowicza 11/12, 80-952 Gdańsk, Poland
| | - Joanna Krakowiak
- Department of Physical Chemistry, Chemical Faculty, Gdańsk University of Technology, Narutowicza 11/12, 80-952 Gdańsk, Poland
| | - Janusz Stangret
- Department of Physical Chemistry, Chemical Faculty, Gdańsk University of Technology, Narutowicza 11/12, 80-952 Gdańsk, Poland
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García Martínez A, Teso Vilar E, García Fraile A, Martínez-Ruiz P. Density functional theory study of self-association of N-methylformamide and its effect on intramolecular and intermolecular geometrical parameters and thecis/transpopulation. J Chem Phys 2006; 124:234305. [PMID: 16821916 DOI: 10.1063/1.2204910] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The single-point total energy (E) of several acyclic and cyclic oligomers of N-methylformamide (NMF) was computed by the first time without any geometrical restriction, using the B3LYP6-31G* method of the density functional theory in order to determine the effect of self-association on intramolecular geometrical parameters of cis- and trans-NMF, the intermolecular distances of the hydrogen-bonding chains formed by NMF as well as intermolecular association energies including counterpoise corrections. It is concluded that liquid NMF exists mainly as polymers formed by self-association of trans-NMF units, whereas the cis-NMF isomer occurs as isolated units inserted along the chains. These computational results are in accordance with the experimentally determined predominance (ca. 90%) of trans-NMF population by means of (1)H- NMR and other spectroscopic techniques, but in severe contradiction with a recent interpretation of x-ray diffraction data on liquid NMF, postulating a cyclic trimer of cis-NMF (c-C(3)) as the predominating species. The counterpoise-corrected values of the association energy, DeltaE(CP), calculated for cyclic oligomers, increase with the polymerization degree (n) revealing a high grade of cooperative effect for amidic hydrogen-bonded chains. Noteworthy, the difference between the DeltaE(CP) values of the cyclic cis- and trans-homooligomers of NMF is positive for n=2 and 3 but negative for n > or =4.
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Affiliation(s)
- A García Martínez
- Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avenida Complutense s/n, E-28040 Madrid, Spain.
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Maeyama T, Negishi Y, Tsukuda T, Yagi I, Mikami N. Electron localization in negatively charged formamide clusters studied by photodetachment spectroscopy. Phys Chem Chem Phys 2006; 8:827-33. [PMID: 16482324 DOI: 10.1039/b514656a] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Size-dependent features of the electron localization in negatively charged formamide clusters (FAn-, n = 5-21) have been studied by photodetachment spectroscopy. In the photoelectron spectra for all the sizes studied, two types of bands due to different isomers of anions were found. The low binding energy band peaking around 1 eV is assigned to the solvated electron state by relative photodetachment cross-section measurements in the near-infrared region. It is suggested that nascent electron trapping is dominated by formation of the solvated electron. The higher energy band originates from the covalent anion state generated after a significant relaxation process, which exhibits a rapid increase of electron binding energy as a function of the cluster size. A unique behavior showing a remarkable band intensity of the higher energy band was found only for n = 9.
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Affiliation(s)
- Toshihiko Maeyama
- Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai, 980-8578, Japan.
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Hammer NI, Roscioli JR, Johnson MA, Myshakin EM, Jordan KD. Infrared Spectrum and Structural Assignment of the Water Trimer Anion. J Phys Chem A 2005; 109:11526-30. [PMID: 16354044 DOI: 10.1021/jp053769c] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The bending vibrational spectrum of the perdeutero isotopomer of the water trimer anion has been measured and compared with spectra calculated using the MP2, CCSD, and Becke3LYP electronic structure methods. Due to its low electron binding energy (approximately 150 meV), only the OD bending region of the IR spectrum of (D2O)3(-) is accessible experimentally, with electron ejection dominating at higher photon energies. The calculated spectrum of the isomer having three water molecules arranged in a chain agrees best with the experimental spectrum. In the chain isomer, the excess electron is bound to the terminal water monomer with two dangling OH groups. This is consistent with the electron binding mechanism established previously for the (H2O)n(-) (n = 2, 4-6) anions.
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Affiliation(s)
- N I Hammer
- Sterling Chemistry Laboratory, Yale University, P.O. Box 208107, New Haven, Connecticut 06520, USA
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Hammami F, Nasr S, Bellissent-Funel MC. Neutron scattering study of the H-bond network in amorphous N-methylformamide. J Chem Phys 2005; 122:064505. [PMID: 15740386 DOI: 10.1063/1.1848512] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Original investigations of structural properties in noncrystalline solid N-methylformamide (HCONHCH(3)) are presented in this paper. After description of the sample preparation, the elastic neutron scattering formalism is applied to deduce the coherent scattering cross section for amorphous N-methylformamide. The contribution of each possible monomer (cis or trans) is computed and the corresponding distinct structure factor is deduced. Our measurements clearly show that the hydrogen-bond network occurs in amorphous N-methylformamide between C=O and N-H groups. The experimental spectra are consistent with an open-chain structure similar to the one existing in the crystalline form. The more probable clusters that have been identified in the liquid are also examined.
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Affiliation(s)
- Férid Hammami
- Laboratoire Physico-Chimie des Matériaux, Département de Physique, Faculté des Sciences de Monastir, Monastir 5019, Tunisia
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Kobori Y, Yago T, Akiyama K, Tero-Kubota S, Sato H, Hirata F, Norris JR. Superexchange Electron Tunneling Mediated by Solvent Molecules: Pulsed Electron Paramagnetic Resonance Study on Electronic Coupling in Solvent-Separated Radical Ion Pairs. J Phys Chem B 2004. [DOI: 10.1021/jp036925t] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Yasuhiro Kobori
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637
| | - Tomoaki Yago
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aobaku, Sendai 980-8577, Japan
| | - Kimio Akiyama
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aobaku, Sendai 980-8577, Japan
| | - Shozo Tero-Kubota
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aobaku, Sendai 980-8577, Japan
| | - Hirofumi Sato
- Department of Molecular Engineering, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Fumio Hirata
- Department of Theoretical Studies, Institute of Molecular Science and School of Mathematical and Physical Science, The Graduate University for Advanced Studies, Okazaki 444-8585, Japan
| | - James R. Norris
- Department of Chemistry and Institute of Biophysical Dynamics, University of Chicago, Chicago, Illinois 60637
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Li P, Bu Y, Ai H. Theoretical Determinations of Ionization Potential and Electron Affinity of Glycinamide Using Density Functional Theory. J Phys Chem A 2004. [DOI: 10.1021/jp035951o] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Ping Li
- Institute of Theoretical Chemistry, Shandong University, Jinan 250100, P. R. China, and Department of Chemistry, Qufu Normal University, Qufu 273165, P. R. China
| | - Yuxiang Bu
- Institute of Theoretical Chemistry, Shandong University, Jinan 250100, P. R. China, and Department of Chemistry, Qufu Normal University, Qufu 273165, P. R. China
| | - Hongqi Ai
- Institute of Theoretical Chemistry, Shandong University, Jinan 250100, P. R. China, and Department of Chemistry, Qufu Normal University, Qufu 273165, P. R. China
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Hammer NI, Hinde RJ, Compton RN, Diri K, Jordan KD, Radisic D, Stokes ST, Bowen KH. Dipole-bound anions of highly polar molecules: Ethylene carbonate and vinylene carbonate. J Chem Phys 2004; 120:685-90. [PMID: 15267903 DOI: 10.1063/1.1629669] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Results of experimental and theoretical studies of dipole-bound negative ions of the highly polar molecules ethylene carbonate (EC, C3H4O3, mu=5.35 D) and vinylene carbonate (VC, C3H2O3, mu=4.55 D) are presented. These negative ions are prepared in Rydberg electron transfer (RET) reactions in which rubidium (Rb) atoms, excited to ns or nd Rydberg states, collide with EC or VC molecules to produce EC- or VC- ions. In both cases ions are produced only when the Rb atoms are excited to states described by a relatively narrow range of effective principal quantum numbers, n*; the greatest yields of EC- and VC- are obtained for n*(max)=9.0+/-0.5 and 11.6+/-0.5, respectively. Charge transfer from low-lying Rydberg states of Rb is characteristic of a large excess electron binding energy (Eb) of the neutral parent; employing the previously derived empirical relationship Eb=23/n*(max)(2.8) eV, the electron binding energies are estimated to be 49+/-8 meV for EC and 24+/-3 meV for VC. Electron photodetachment studies of EC- show that the excess electron is bound by 49+/-5 meV, in excellent agreement with the RET results, lending credibility to the empirical relationship between Eb and n*(max). Vertical electron affinities for EC and VC are computed employing aug-cc-pVDZ atom-centered basis sets supplemented with a (5s5p) set of diffuse Gaussian primitives to support the dipole-bound electron; at the CCSD(T) level of theory the computed electron affinities are 40.9 and 20.1 meV for EC and VC, respectively.
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Affiliation(s)
- Nathan I Hammer
- Department of Chemistry, The University of Tennessee, Knoxville, Tennessee 37996, USA
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Skarmoutsos I, Samios J. Molecular dynamics of cis/transN-methylformamide liquid mixture using a new optimized all atom rigid force field. Chem Phys Lett 2004. [DOI: 10.1016/j.cplett.2003.11.096] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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35
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Hammami F, Bahri M, Nasr S, Jaidane N, Oummezzine M, Cortes R. Short-range order in liquid N-methylformamide HCONHCH3, as studied by x-ray scattering and density functional theory calculations. J Chem Phys 2003. [DOI: 10.1063/1.1592513] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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36
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Abstract
The problem of the binding of an excess electron to polar molecules and their clusters has long fascinated researchers. Although excess electrons bound to such species tend to be very extended spatially and to have little spatial overlap with the valence electrons of the neutral molecules, inclusion of electron correlation effects is essential for quantitatively describing the electron binding. The major electron correlation contribution may be viewed as a dispersion interaction between the excess electron and the electrons of the molecule or cluster. Recent work using a one-electron Drude model to describe excess electrons interacting with polar molecules is reviewed.
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Affiliation(s)
- Kenneth D Jordan
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, USA.
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Chevreau H, Gardebien F, Dézarnaud-Dandine C, Sevin A. On the Potential Catalytic Role of Electron Capture in Gas-Phase Condensation Reactions: A Theoretical Exploratory Study of the CH2O2 and CH3ON Systems. Chemphyschem 2001; 2:583-90. [DOI: 10.1002/1439-7641(20011015)2:10<583::aid-cphc583>3.0.co;2-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2000] [Indexed: 11/11/2022]
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38
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Dipole-bound anion of 1,3-butanediol. Ab initio and Rydberg electron transfer spectroscopy study. Chem Phys Lett 2001. [DOI: 10.1016/s0009-2614(00)01455-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Desfrançois C, Carles S, Schermann JP. Weakly bound clusters of biological interest. Chem Rev 2000; 100:3943-62. [PMID: 11749335 DOI: 10.1021/cr990061j] [Citation(s) in RCA: 202] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- C Desfrançois
- Laboratoire de Physique des Lasers, Université Paris Nord, Villetaneuse, 93430, France
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Desfrançois C, Abdoul-Carime H, Carles S, Périquet V, Schermann JP, Smith DMA, Adamowicz L. Experimental and theoreticalab initiostudy of the influence of N-methylation on the dipole-bound electron affinities of thymine and uracil. J Chem Phys 1999. [DOI: 10.1063/1.479175] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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