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Chiang YJ, Huang WC, Han CH, Liu CL, Tsai CC, Hu WP. Near-edge x-ray absorption fine structure spectra and specific dissociation of small peptoid molecules. J Chem Phys 2024; 160:074305. [PMID: 38380751 DOI: 10.1063/5.0188660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 01/31/2024] [Indexed: 02/22/2024] Open
Abstract
In this study, the total ion yield near-edge x-ray absorption fine structure spectra of four similar peptoid molecules, which differ in the numbers and positions of methyl groups, were investigated experimentally and theoretically. At each excitation energy, the intensity and branching ratio of each ionic product were measured. At a few resonant excitation energies, a specific dissociation of the C-CO bond at the nitrogen and oxygen K-edges and of the N-CO bond at the carbon K-edge was dominant, which correlated well with the predicted destination antibonding orbitals of the core electron excitation. These specific dissociation mechanisms of small peptoid molecules could provide insights into similar phenomena that occur in peptide molecules.
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Affiliation(s)
- Yu-Ju Chiang
- Scientific Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - Wan-Chou Huang
- Scientific Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - Chou-Hsun Han
- Scientific Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - Chen-Lin Liu
- Scientific Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - Cheng-Cheng Tsai
- Department of Chemistry and Biochemistry, National Chung Cheng University, Chia-Yi 62102, Taiwan
| | - Wei-Ping Hu
- Department of Chemistry and Biochemistry, National Chung Cheng University, Chia-Yi 62102, Taiwan
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2
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Gerlach M, Schaffner D, Preitschopf T, Karaev E, Bozek J, Holzmeier F, Fischer I. X-ray induced fragmentation of fulminic acid, HCNO. J Chem Phys 2023; 159:114306. [PMID: 37721327 DOI: 10.1063/5.0167395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 08/24/2023] [Indexed: 09/19/2023] Open
Abstract
The fragmentation of fulminic acid, HCNO, after excitation and ionization of core electrons was investigated using Auger-electron-photoion coincidence spectroscopy. A considerable degree of site-selectivity is observed. Ionization of the carbon and oxygen 1s electron leads to around 70% CH+ + NO+, while ionization at the central N-atom produces only 37% CH+ + NO+, but preferentially forms O+ + HCN+ and O+ + CN+. The mass-selected Auger-electron spectra show that these fragments are associated with higher binding energy final states. Furthermore, ionization of the C 1s electron leads to a higher propensity for C-H bond fission compared to O 1s ionization. Following resonant Auger-Meitner decay after 1s → 3π excitation, 12 different ionic products are formed. At the C 1s edge, the parent ion HCNO+ is significantly more stable compared to the other two edges, which we also attribute to the higher contribution of final states with low binding energies in the C 1s resonant Auger electron spectra.
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Affiliation(s)
- Marius Gerlach
- Institute of Physical and Theoretical Chemistry, University of Würzburg, 97074 Würzburg, Germany
| | - Dorothee Schaffner
- Institute of Physical and Theoretical Chemistry, University of Würzburg, 97074 Würzburg, Germany
| | - Tobias Preitschopf
- Institute of Physical and Theoretical Chemistry, University of Würzburg, 97074 Würzburg, Germany
| | - Emil Karaev
- Institute of Physical and Theoretical Chemistry, University of Würzburg, 97074 Würzburg, Germany
| | - John Bozek
- Synchrotron SOLEIL, 91192 Gif-sur-Yvette, France
| | | | - Ingo Fischer
- Institute of Physical and Theoretical Chemistry, University of Würzburg, 97074 Würzburg, Germany
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3
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Sysoev VI, Gurova OA, Fedoseeva YV, Gusel'nikov AV, Makarova AA, Okotrub AV, Bulusheva LG. Tuning humidity sensing properties via grafting fluorine and nitrogen-containing species on single-walled carbon nanotubes. Phys Chem Chem Phys 2023; 25:19976-19985. [PMID: 37461330 DOI: 10.1039/d3cp01550e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2023]
Abstract
The effect of humidity on the electrical conductivity of single-walled carbon nanotube (SWCNT) films depends on both the conductivity of individual nanotubes and the electrical contacts between them. Here, we study these factors by comparing the sensor response of nanotubes with fluorine- and nitrogen-containing groups attached to the sidewalls. Experiments carried out in a wide range of relative humidity (RH) at room and elevated temperatures showed that the conductivity of non-functionalized SWCNTs and contacts between them decreases upon the adsorption of water molecules. Covalent fluorination reduces the conductivity of SWCNTs and significantly increases the sensitivity of the film to low concentrations of water vapor. The response at high RH decreases due to the large number of water molecules adsorbed on the conductive regions of the nanotubes. As a result of substitutional reactions of fluorinated SWCNTs with dimethylformamide and ethylenediamine, nitrogen-containing groups are added, the amount of which, however, is much less than the amount of fluorine. This modification of the SWCNTs improves intertube contacts in the film and increases the surface area for water adsorption. Our results show that an increase in the number of functional groups on the SWCNT surface enhances the sensitivity of the sensor to low water concentrations and worsens the response at high RH. SWCNTs modified with ethylenediamine have the highest sensitivity over the entire range of RH.
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Affiliation(s)
- Vitalii I Sysoev
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences, 3 Acad. Lavrentiev ave., Novosibirsk 630090, Russia.
| | - Olga A Gurova
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences, 3 Acad. Lavrentiev ave., Novosibirsk 630090, Russia.
| | - Yuliya V Fedoseeva
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences, 3 Acad. Lavrentiev ave., Novosibirsk 630090, Russia.
| | - Artem V Gusel'nikov
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences, 3 Acad. Lavrentiev ave., Novosibirsk 630090, Russia.
| | - Anna A Makarova
- Physical Chemistry, Institute of Chemistry and Biochemistry, Free University of Berlin, Arnimallee 22, 14195 Berlin, Germany
| | - Alexander V Okotrub
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences, 3 Acad. Lavrentiev ave., Novosibirsk 630090, Russia.
| | - Lyubov G Bulusheva
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences, 3 Acad. Lavrentiev ave., Novosibirsk 630090, Russia.
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Salen P, Schio L, Richter R, Alagia M, Stranges S, Falcinelli S, Zhaunerchyk V. Electronic state influence on selective bond breaking of core-excited nitrosyl chloride (ClNO). J Chem Phys 2022; 157:124306. [DOI: 10.1063/5.0106642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The potential for selective bond breaking of a small molecule was investigated with electron-spectroscopy and electron-ion coincidence experiments on ClNO. The electron spectra were measured upon direct valence photo-ionization and upon resonant core-excitation at the N 1s- and O 1s-edges followed by emission of resonant Auger (RA) electrons. The RA spectra were analyzed with particular emphasis on the assignment of the participator and spectator states. The latter are of special relevance for investigations of how distinct electronic configurations influence selective bond breaking. The electron-ion coincidence measurements provided branching fractions of the produced ion-fragments as a function of electron binding energy. It explicitly demonstrates the influence of the final electronic states created after the photo-ionization and RA decay, on the fragmentation. In particular, we observe a significantly different branching fraction for spectator states compared with participator states. The bonds broken for the spectator states are also found to correlate with the anti-bonding character of the spectator-electron orbital.
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Affiliation(s)
- Peter Salen
- Physics and Astronomy, Uppsala Universitet, Sweden
| | - Luca Schio
- IOM CNR Laboratorio TASC, 34012 Trieste, Italy
| | | | | | - Stefano Stranges
- Chemistry and Technologies of Drugs, University of Rome La Sapienza, Italy
| | - Stefano Falcinelli
- Department of Civil and Environmental Engineering, University of Perugia, Italy
| | - Vitali Zhaunerchyk
- Department of Physics, University of Gothenburg Department of Physics, Sweden
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5
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Gerlach M, Fantuzzi F, Wohlfart L, Kopp K, Engels B, Bozek J, Nicolas C, Mayer D, Gühr M, Holzmeier F, Fischer I. Fragmentation of isocyanic acid, HNCO, following core excitation and ionization. J Chem Phys 2021; 154:114302. [PMID: 33752348 DOI: 10.1063/5.0044506] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
We report a study on the fragmentation of core-ionized and core-excited isocyanic acid, HNCO, using Auger-electron/photoion coincidence spectroscopy. Site-selectivity is observed both for normal and resonant Auger electron decay. Oxygen 1s ionization leads to the CO+ + NH+ ion pairs, while nitrogen 1s ionization results in three-body dissociation and an efficient fragmentation of the H-N bond in the dication. Upon 1s → 10a' resonant excitation, clear differences between O and N sites are discernible as well. In both cases, the correlation between the dissociation channel and the binding energy of the normal Auger electrons indicates that the fragmentation pattern is governed by the excess energy available in the final ionic state. High-level multireference calculations suggest pathways to the formation of the fragment ions NO+ and HCO+, which are observed although the parent compound contains neither N-O nor H-C bonds. This work contributes to the goal to achieve and understand site-selective fragmentation upon ionization and excitation of molecules with soft x-ray radiation.
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Affiliation(s)
- Marius Gerlach
- Institute of Physical and Theoretical Chemistry, University of Würzburg, 97074 Würzburg, Germany
| | - Felipe Fantuzzi
- Institute of Physical and Theoretical Chemistry, University of Würzburg, 97074 Würzburg, Germany
| | - Lilith Wohlfart
- Institute of Physical and Theoretical Chemistry, University of Würzburg, 97074 Würzburg, Germany
| | - Karina Kopp
- Institute of Physical and Theoretical Chemistry, University of Würzburg, 97074 Würzburg, Germany
| | - Bernd Engels
- Institute of Physical and Theoretical Chemistry, University of Würzburg, 97074 Würzburg, Germany
| | - John Bozek
- Synchrotron SOLEIL, 91192 Gif-sur-Yvette, France
| | | | - Dennis Mayer
- Institut für Physik und Astronomie, Universität Potsdam, 14476 Potsdam-Golm, Germany
| | - Markus Gühr
- Institut für Physik und Astronomie, Universität Potsdam, 14476 Potsdam-Golm, Germany
| | - Fabian Holzmeier
- Dipartimento di Fisica, Politecnico di Milano, 20133 Milano, Italy
| | - Ingo Fischer
- Institute of Physical and Theoretical Chemistry, University of Würzburg, 97074 Würzburg, Germany
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6
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Salén P, Schio L, Richter R, Alagia M, Stranges S, Zhaunerchyk V. Investigating core-excited states of nitrosyl chloride (ClNO) and their break-up dynamics following Auger decay. J Chem Phys 2018; 149:164305. [DOI: 10.1063/1.5047262] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Peter Salén
- FREIA Laboratory, Department of Physics and Astronomy, Uppsala University, 751 20 Uppsala, Sweden
- Department of Physics, Stockholm University, 106 91 Stockholm, Sweden
| | - Luca Schio
- IOM-CNR Tasc, SS-14, Km 163.5 Area Science Park, Basovizza, I-34149 Trieste, Italy
- Department of Basic and Applied Sciences for Engineering (SBAI), Sapienza University, I-00185 Rome, Italy
| | - Robert Richter
- Elettra-Sincrotrone Trieste, Area Science Park, 34149 Basovizza, Trieste, Italy
| | - Michele Alagia
- IOM-CNR Tasc, SS-14, Km 163.5 Area Science Park, Basovizza, I-34149 Trieste, Italy
| | - Stefano Stranges
- IOM-CNR Tasc, SS-14, Km 163.5 Area Science Park, Basovizza, I-34149 Trieste, Italy
- Dipartimento di Chimica e Tecnologie del Farmaco, Universitá Sapienza, Roma I-00185 Italy
| | - Vitali Zhaunerchyk
- Department of Physics, University of Gothenburg, 412 96 Gothenburg, Sweden
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