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Wu X, Zhang C, Gu X, Fittschen C, Loison JC, Roy Chowdhury M, Garcia GA, Nahon L, Tang X. Photoionization and Dissociative Photoionization of Acetaldehyde in the 10.0-13.7 eV Range by Synchrotron Photoelectron Photoion Coincidence Spectroscopy. Chemphyschem 2024; 25:e202400208. [PMID: 38594204 DOI: 10.1002/cphc.202400208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 04/09/2024] [Accepted: 04/09/2024] [Indexed: 04/11/2024]
Abstract
Photoionization and dissociative photoionization of acetaldehyde (CH3CHO) in the 10.0-13.7 eV energy range are studied by using synchrotron radiation double imaging photoelectron photoion coincidence spectroscopy (i2PEPICO). The X2A' and A2A" electronic states of CH3CHO+ as well as the Franck-Condon gap region between these two states have been populated with several vibrational sequences and assigned in the high-resolution slow photoelectron spectrum (SPES). The adiabatic ionization energies (AIEs) of the X2A' and A2A" states are measured at 10.228±0.006 and 12.52±0.05 eV, respectively. The present results show that the X2A' state is a stable state while the A2A" state is fully dissociative to produce CH3CO+, CHO+ and CH4 + fragment ions. The 0 K appearance energies (AE0K) of CH3CO+ and CHO+ fragment ions are determined through the modeling of the breakdown diagram, i. e., AE0K(CH3CO+)=10.89±0.01 eV (including a reverse barrier of ~0.19 eV) and AE0K(CHO+)=11.54±0.05 eV. In addition, the dissociation mechanisms of CH3CHO+ including statistical dissociation, direct bond breaking and isomerization are discussed with the support of the calculated dissociation limits and transition state energies.
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Affiliation(s)
- Xiangkun Wu
- Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Sciences, Chinese Academy of Sciences, Hefei, 230031, Anhui, China
| | - Cuihong Zhang
- Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Sciences, Chinese Academy of Sciences, Hefei, 230031, Anhui, China
- University Lille, CNRS, UMR 8522, PC2A - Physicochimie des Processus de Combustion et de l'Atmosphère, F-59000, Lille, France
| | - Xuejun Gu
- Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Sciences, Chinese Academy of Sciences, Hefei, 230031, Anhui, China
| | - Christa Fittschen
- University Lille, CNRS, UMR 8522, PC2A - Physicochimie des Processus de Combustion et de l'Atmosphère, F-59000, Lille, France
| | - Jean-Christophe Loison
- Institut des Sciences Moléculaires (ISM), CNRS, Univ. Bordeaux, 351 cours de la Libération, 33400, Talence, France
| | | | - Gustavo A Garcia
- Synchrotron SOLEIL, L'Orme des Merisiers, St. Aubin, BP 48, 91192, Gif sur Yvette, France
| | - Laurent Nahon
- Synchrotron SOLEIL, L'Orme des Merisiers, St. Aubin, BP 48, 91192, Gif sur Yvette, France
| | - Xiaofeng Tang
- Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Sciences, Chinese Academy of Sciences, Hefei, 230031, Anhui, China
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Bhavsar N, Shastri A, Vinodkumar PC, Vinodkumar M. Electron impact scattering and electronic excitation in glycolaldehyde: The first ever detected sugar in space. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024; 304:123397. [PMID: 37716041 DOI: 10.1016/j.saa.2023.123397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 08/16/2023] [Accepted: 09/10/2023] [Indexed: 09/18/2023]
Abstract
Detailed theoretical investigations on structural, spectroscopic and electron scattering cross sections of glycolaldehyde, the first ever detected sugar in space are reported in this work. Spectroscopic calculations are performed on the ground and excited states of glycolaldehyde using density functional theory (DFT) and time-dependent density functional theory (TDDFT), respectively. The optimized geometrical parameters and vibrational spectrum are in good agreement with the earlier reported work. Vertical excited state (VES) energies at the TDDFT/B3LYP/aug-cc-PVQZ level of theory along with detailed assignments are reported up to 30 transitions. The TDDFT predicted Rydberg series energies are compared with the Rydberg series of glycolaldehyde converging to its first IP, computed using the standard Rydberg formula and are found to be in good agreement. In the absence of sufficient experimental data on excited states of glycolaldehyde, the theoretical results are validated by comparison of VES calculations performed at the same level of theory with the available experimental data for an analogous molecule viz. acetaldehyde. Triplet excited-state energies for glycolaldehyde are reported here for the first time. Electron impact cross section calculations in the energy range 0.1 to 20 eV are carried out using ab-initio R-matrix method. We have detected one π* shape resonance in all the three models viz. SE, SEP and CC, which may also lead to a possible fragmentation channel wherein a hydrogen atom is removed from the molecule forming a glycolaldehyde dehydrogenated anionic radical (C2H3O2-). The π* shape resonance is correlated with the corresponding molecular orbital electronic structure calculations. Additionally, differential, electronic excitation, ionization and total cross sections are reported here for the first time.
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Affiliation(s)
- Nirali Bhavsar
- Government Science College, Varachha, Surat 395006, Gujarat, India; V.P. & R.P.T.P. Science College, Vallabh Vidyanagar 388120, Gujarat, India
| | - Aparna Shastri
- Atomic & Molecular Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| | - P C Vinodkumar
- P. D. Patel Institute of Applied Science, CHARUSAT, Changa 388421, Gujarat, India
| | - Minaxi Vinodkumar
- V.P. & R.P.T.P. Science College, Vallabh Vidyanagar 388120, Gujarat, India.
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Mahla S, Antony B. Positron scattering from structurally related biomolecules. RSC Adv 2024; 14:1397-1406. [PMID: 38174274 PMCID: PMC10763659 DOI: 10.1039/d3ra06227a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 12/19/2023] [Indexed: 01/05/2024] Open
Abstract
We report the integral elastic, momentum transfer, and inelastic (positronium formation and ionisation) cross sections for positron scattering from structurally related molecules. The molecules chosen for the current investigation are formamide, formylphosphine, formic acid, N-methylformamide, acetone, acetic acid, and formaldehyde. The cross sections were calculated using the optical potential approach and the complex scattering potential-ionisation contribution method for impact energies between 1 and 5 keV. A sizable repository of data is now available for positron scattering from various atoms and molecules; however, data on the impact of positrons on current targets is still scarce and fragmented. While most cross sections are the first of their kind, we analyze our total cross sections (TCSs) with the previous literature available, which has become attractive to researchers trying to model the tracks of charged particles in matter. TCSs have recently seen a resurgence in popularity thanks to their utility in specifying the mean-free path between the collisions of such simulations. We find good qualitative convergence between experimental and theoretical results below and above the positronium formation threshold. However, around the threshold region, a significant discrepancy is encountered, which can be accounted for due to the experiment's lack of forward angle scattering effect discrimination. This level of agreement evolves to become quantitative at intermediate and higher energies.
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Affiliation(s)
- Sapna Mahla
- Department of Physics, Indian Institute of Technology (ISM) Dhanbad JH 826004 India
| | - Bobby Antony
- Department of Physics, Indian Institute of Technology (ISM) Dhanbad JH 826004 India
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Abderahem M, Zhang Y, Liu Z, Shan X, Chen X. Vibrational effects on the valence electronic structure of acetaldehyde: An electron momentum spectroscopy investigation. Chem Phys 2023. [DOI: 10.1016/j.chemphys.2023.111892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
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Vadhel S, Jani T, Shastri A, Pothodichackra V, Vinodkumar M. Electronic Excitations and Low-Energy Electron-Induced Scattering Studies of Acrylonitrile (CH 2CHCN). J Phys Chem A 2022; 126:8136-8155. [DOI: 10.1021/acs.jpca.2c05186] [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)
- Sagar Vadhel
- V.P. & R.P.T.P. Science College, Vallabh Vidyanagar 388120, Gujarat, India
| | - Tejas Jani
- V.P. & R.P.T.P. Science College, Vallabh Vidyanagar 388120, Gujarat, India
| | - Aparna Shastri
- Atomic and Molecular Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400085, India
| | | | - Minaxi Vinodkumar
- V.P. & R.P.T.P. Science College, Vallabh Vidyanagar 388120, Gujarat, India
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Prajapati D, Vinodkumar PC, Limbachiya C, Vinodkumar M. Theoretical investigations of structural, spectroscopic and electron collision data of acetone. Mol Phys 2021. [DOI: 10.1080/00268976.2021.1948124] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- D. Prajapati
- Department of Physics, Sardar Patel University, Vallabh Vidyanagar, India
- Shree M R Arts & Science College, Rajpipla, India
| | - P. C. Vinodkumar
- Department of Physics, Sardar Patel University, Vallabh Vidyanagar, India
| | - C. Limbachiya
- Department of Applied Physics, The M. S. University of Baroda, Vadodara, India
| | - M. Vinodkumar
- Electronics Department, V.P. & R.P.T.P. Science College, Vallabh Vidyanagar, India
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Limbachiya C, Chaudhari A, Desai H, Vinodkumar M. Electron induced chemistry of thioformaldehyde. RSC Adv 2015. [DOI: 10.1039/c5ra19662k] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
A comprehensive theoretical study was carried out for electron interactions with thioformaldehyde (H2CS) over a wide range of impact energies (0.01 eV to 5000 eV).
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Affiliation(s)
- Chetan Limbachiya
- Department of Applied Physics
- The M. S. University Baroda
- Vadodara – 390001
- India
| | | | - Hardik Desai
- Department of Physics
- Sardar Patel University
- India
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