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Travnikova O, Patanen M, Söderström J, Lindblad A, Kas JJ, Vila FD, Céolin D, Marchenko T, Goldsztejn G, Guillemin R, Journel L, Carroll TX, Børve KJ, Decleva P, Rehr JJ, Mårtensson N, Simon M, Svensson S, Sæthre LJ. Energy-Dependent Relative Cross Sections in Carbon 1s Photoionization: Separation of Direct Shake and Inelastic Scattering Effects in Single Molecules. J Phys Chem A 2019; 123:7619-7636. [PMID: 31386367 DOI: 10.1021/acs.jpca.9b05063] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We demonstrate that the possibility of monitoring relative photoionization cross sections over a large photon energy range allows us to study and disentangle shake processes and intramolecular inelastic scattering effects. In this gas-phase study, relative intensities of the carbon 1s photoelectron lines from chemically inequivalent carbon atoms in the same molecule have been measured as a function of the incident photon energy in the range of 300-6000 eV. We present relative cross sections for the chemically shifted carbon 1s lines in the photoelectron spectra of ethyl trifluoroacetate (the "ESCA" molecule). The results are compared with those of methyl trifluoroacetate and S-ethyl trifluorothioacetate as well as a series of chloro-substituted ethanes and 2-butyne. In the soft X-ray energy range, the cross sections show an extended X-ray absorption fine structure type of wiggles, as was previously observed for a series of chloroethanes. The oscillations are damped in the hard X-ray energy range, but deviations of cross-section ratios from stoichiometry persist, even at high energies. The current findings are supported by theoretical calculations based on a multiple scattering model. The use of soft and tender X-rays provides a more complete picture of the dominant processes accompanying photoionization. Such processes reduce the main photoelectron line intensities by 20-60%. Using both energy ranges enabled us to discern the process of intramolecular inelastic scattering of the outgoing electron, whose significance is otherwise difficult to assess for isolated molecules. This effect relates to the notion of the inelastic mean free path commonly used in photoemission studies of clusters and condensed matter.
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Affiliation(s)
- Oksana Travnikova
- LCPMR, CNRS, Sorbonne Université, UMR7614 Paris, France.,Synchrotron Soleil, L'Orme des Merisiers, Saint-Aubin, F-91192 Gif-sur-Yvette, France
| | - Minna Patanen
- Nano and Molecular Systems Research Unit, Faculty of Science, University of Oulu, P.O. Box 3000, 90014 Oulu, Finland
| | - Johan Söderström
- Department of Physics and Astronomy, Uppsala University, P.O. Box 516, 75120 Uppsala, Sweden
| | | | - Joshua J Kas
- Department of Physics, University of Washington, Box 351560, Seattle, Washington 98195-1560, United States
| | - Fernando D Vila
- Department of Physics, University of Washington, Box 351560, Seattle, Washington 98195-1560, United States
| | - Denis Céolin
- Synchrotron Soleil, L'Orme des Merisiers, Saint-Aubin, F-91192 Gif-sur-Yvette, France
| | - Tatiana Marchenko
- LCPMR, CNRS, Sorbonne Université, UMR7614 Paris, France.,Synchrotron Soleil, L'Orme des Merisiers, Saint-Aubin, F-91192 Gif-sur-Yvette, France
| | | | - Renaud Guillemin
- LCPMR, CNRS, Sorbonne Université, UMR7614 Paris, France.,Synchrotron Soleil, L'Orme des Merisiers, Saint-Aubin, F-91192 Gif-sur-Yvette, France
| | - Loïc Journel
- LCPMR, CNRS, Sorbonne Université, UMR7614 Paris, France.,Synchrotron Soleil, L'Orme des Merisiers, Saint-Aubin, F-91192 Gif-sur-Yvette, France
| | - Thomas X Carroll
- Division of Natural Sciences, Keuka College, Keuka Park, New York 14478, United States
| | - Knut J Børve
- Department of Chemistry, University of Bergen, Allégaten 41, NO-5007 Bergen, Norway
| | - Piero Decleva
- Dipartimento di Scienze Chimiche e Farmaceutiche, Universitá di Trieste and IOM-CNR, 34127 Trieste, Italy
| | - John J Rehr
- Department of Physics, University of Washington, Box 351560, Seattle, Washington 98195-1560, United States
| | - Nils Mårtensson
- Department of Physics and Astronomy, Uppsala University, P.O. Box 516, 75120 Uppsala, Sweden
| | - Marc Simon
- LCPMR, CNRS, Sorbonne Université, UMR7614 Paris, France.,Synchrotron Soleil, L'Orme des Merisiers, Saint-Aubin, F-91192 Gif-sur-Yvette, France
| | - Svante Svensson
- Department of Physics and Astronomy, Uppsala University, P.O. Box 516, 75120 Uppsala, Sweden
| | - Leif J Sæthre
- Department of Chemistry, University of Bergen, Allégaten 41, NO-5007 Bergen, Norway
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Löytynoja T, Harczuk I, Jänkälä K, Vahtras O, Ågren H. Quantum-classical calculations of X-ray photoelectron spectra of polymers-Polymethyl methacrylate revisited. J Chem Phys 2017; 146:124902. [PMID: 28388163 DOI: 10.1063/1.4978941] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In this work, we apply quantum mechanics/molecular mechanics (QM/MM) approach to predict core-electron binding energies and chemical shifts of polymers, obtainable via X-ray photoelectron spectroscopy(XPS), using polymethyl methacrylate as a demonstration example. The results indicate that standard parametrizations of the quantum part (basis sets, level of correlation) and the molecular mechanics parts (decomposed charges, polarizabilities, and capping technique) are sufficient for the QM/MM model to be predictive for XPS of polymers. It is found that the polymer environment produces contributions to the XPS binding energies that are close to monotonous with the number of monomer units, totally amounting to approximately an eV decrease in binding energies. In most of the cases, the order of the shifts is maintained, and even the relative size of the differential shifts is largely preserved. The coupling of the internal core-hole relaxation to the polymer environment is found to be weak in each case, amounting only to one or two tenths of an eV. The main polymeric effect is actually well estimated already at the frozen orbital level of theory, which in turn implies a substantial computational simplification. These conclusions are best represented by the cases where the ionized monomer and its immediate surrounding are treated quantum mechanically. If the QM region includes only a single monomer, a couple of anomalies are spotted, which are referred to the QM/MM interface itself and to the neglect of a possible charge transfer.
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Affiliation(s)
- T Löytynoja
- Nano and Molecular Systems Research Unit, University of Oulu, P.O. Box 3000, FIN-90014 Oulu, Finland
| | - I Harczuk
- Division of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology, SE-106 91 Stockholm, Sweden
| | - K Jänkälä
- Nano and Molecular Systems Research Unit, University of Oulu, P.O. Box 3000, FIN-90014 Oulu, FinlandDivision of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology, SE-106 91 Stockholm, Sweden Laboratory for Nonlinear Optics and Spectroscopy, Siberian Federal University, 660041 Krasnoyarsk, Russia
| | - O Vahtras
- Division of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology, SE-106 91 Stockholm, Sweden
| | - H Ågren
- Division of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology, SE-106 91 Stockholm, Sweden
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Huang JY, Huang HG, Ning YS, Liu QP, Alshahateet SF, Sun YM, Xu GQ. A [4+2]-like cycloaddition of methyl methacrylate on Si(100)-2 x 1. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:11722-8. [PMID: 16316106 DOI: 10.1021/la051559l] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The attachment of methyl methacrylate (MMA) on Si(100)-2x1 was investigated using high-resolution electron energy loss spectroscopy (HREELS), X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), and density functional theory (DFT) calculations. The HREELS spectra of chemisorbed MMA show the disappearance of characteristic vibrations of C=O (1725 cm(-1)) and C(sp(2))-H (3110, 1400, and 962 cm(-1)) coupled with the blue shift of the C=C stretching mode by 34 cm(-1) compared to those of physisorbed molecules. These results clearly demonstrate that both C=C and C=O in MMA directly participate in the interaction with the surface to form a SiCH(2)C(CH(3))=C(OCH(3))OSi species via a [4+2]-like cycloaddition. This binding configuration was further supported by XPS, UPS, and DFT studies.
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Affiliation(s)
- Jing Yan Huang
- Department of Chemistry, National University of Singapore
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Huang JY, Shao YX, Huang HG, Cai YH, Ning YS, Tang HH, Liu QP, Alshahateet SF, Sun YM, Xu GQ. Binding Mechanisms of Methacrylic Acid and Methyl Methacrylate on Si(111)-7×7Effect of Substitution Groups. J Phys Chem B 2005; 109:19831-8. [PMID: 16853564 DOI: 10.1021/jp0531659] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The interaction of methacrylic acid and methyl methacrylate with Si(111)-7 x 7 has been investigated using high-resolution electron energy loss spectroscopy (HREELS) and X-ray photoelectron spectroscopy (XPS). While methacrylic acid chemisorbs dissociatively through O-H bond cleavage, methyl methacrylate is covalently attached to the silicon surface via a [4+2] cycloaddition. The different reaction pathways of these two compounds on Si(111)-7 x 7 demonstrate that the substitution groups play an important role in determining the reaction channels for multifunctional molecules, leading to the desired flexibility in the organic modification of silicon surfaces.
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Affiliation(s)
- Jing Yan Huang
- Department of Chemistry, National University of Singapore, 10 Kent Ridge, Singapore 119260, Singapore
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Keane MP, Correia N, Svensson S, Karlsson L, Wannberg B, Gelius U, Lunell S, Salaneck WR, Lögdlund M, Swanson DB, MacDiarmid AG. Valence and core-shakeup photoelectron spectra of solid polyacetylene and related free model molecules. PHYSICAL REVIEW. B, CONDENSED MATTER 1992; 45:6390-6399. [PMID: 10000403 DOI: 10.1103/physrevb.45.6390] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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