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Cheng X, Wei M, Tian G, Luo Y, Hua W. Vibrationally-Resolved X-ray Photoelectron Spectra of Six Polycyclic Aromatic Hydrocarbons from First-Principles Simulations. J Phys Chem A 2022; 126:5582-5593. [PMID: 35959595 DOI: 10.1021/acs.jpca.2c04426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Vibrationally resolved C 1s X-ray photoelectron spectra (XPS) of a series of six polycyclic aromatic hydrocarbons (PAHs; phenanthrene, coronene, naphthalene, anthracene, tetracene, and pentacene) were computed by combining the full core hole density functional theory and the Franck-Condon simulations with the inclusion of the Duschinsky rotation effect. Simulated spectra of phenanthrene, coronene, and naphthalene agree well with experiments both in core binding energies (BEs) and profiles, which validate the accuracy of our predictions for the rest molecules with no high-resolution experiments. We found that three types of carbons i (inner C), p (peripheral C bonded to three C atoms), and h (peripheral C bonded to an H atom) show decreasing BEs. In linear PAHs (the latter four), h-type carbons further split into h1 or h2 (on inner or edge benzene ring) subtypes with chemical shifts of ca. 0.2-0.4 eV. All major Franck-Condon-active modes are characterized to be in-plane vibrations: low-frequency (<800 cm-1) C-C ring deformation modes play an essential role in determining the peak asymmetries; and for each h-type carbon a high-frequency (ca. 3600 cm-1) C*-H stretching mode is responsible for the high-energy tail. We found that core ionization leads to reduction of all C*-C and C*-H bond lengths and ring deformation with a definite direction. Based on theoretical spectra of four linear PAHs, we found asymptotic relations and anticipated possible spectral features for even larger linear PAHs. Our calculations provide accurate reference spectra for XPS characterizations of PAHs, which are useful in understanding the vibronic coupling effects in this family.
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Affiliation(s)
- Xiao Cheng
- Hefei National Laboratory for Physical Science at the Microscale, University of Science and Technology of China, 230026 Hefei, China.,Department of Theoretical Chemistry and Biology, School of Engineering Sciences in Chemistry, Biotechnology and Health, Royal Institute of Technology, SE-106 91, Stockholm, Sweden
| | - Minrui Wei
- MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing, Department of Applied Physics, School of Science, Nanjing University of Science and Technology, 210094 Nanjing, China
| | - Guangjun Tian
- Key Laboratory for Microstructural Material Physics of Hebei Province, School of Science, Yanshan University, Qinhuangdao 066004, China
| | - Yi Luo
- Hefei National Laboratory for Physical Science at the Microscale, University of Science and Technology of China, 230026 Hefei, China
| | - Weijie Hua
- MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing, Department of Applied Physics, School of Science, Nanjing University of Science and Technology, 210094 Nanjing, China
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2
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Totani R, Grazioli C, Zhang T, Bidermane I, Lüder J, de Simone M, Coreno M, Brena B, Lozzi L, Puglia C. Electronic structure investigation of biphenylene films. J Chem Phys 2017; 146:054705. [PMID: 28178795 DOI: 10.1063/1.4975104] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Photoelectron Spectroscopy (PS) and Near-Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy have been used to investigate the occupied and empty density of states of biphenylene films of different thicknesses, deposited onto a Cu(111) crystal. The obtained results have been compared to previous gas phase spectra and single molecule Density Functional Theory (DFT) calculations to get insights into the possible modification of the molecular electronic structure in the film induced by the adsorption on a surface. Furthermore, NEXAFS measurements allowed characterizing the variation of the molecular arrangement with the film thickness and helped to clarify the substrate-molecule interaction.
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Affiliation(s)
- R Totani
- Department of Physical and Chemical Sciences, University of L'Aquila, via Vetoio, 67100 Coppito L'Aquila, Italy
| | - C Grazioli
- Department of Chemical and Pharmaceutical Sciences, University of Trieste, 34127 Trieste, Italy
| | - T Zhang
- Department of Physics and Astronomy, Uppsala University, P.O. Box 516, SE-751 20 Uppsala, Sweden
| | - I Bidermane
- Institute Methods and Instrumentation for Synchrotron Radiation Research, Helmholtz Zentrum Berlin, Albert-Einstein St. 15, 12489 Berlin, Germany
| | - J Lüder
- Department of Physics and Astronomy, Uppsala University, P.O. Box 516, SE-751 20 Uppsala, Sweden
| | - M de Simone
- CNR-IOM,S.S. 14 km 163.5, I-34149 Trieste, Basovizza, Italy
| | - M Coreno
- CNR-ISM, S.S. 14 km 163.5, I-34149 Trieste, Basovizza, Italy
| | - B Brena
- Department of Physics and Astronomy, Uppsala University, P.O. Box 516, SE-751 20 Uppsala, Sweden
| | - L Lozzi
- Department of Physical and Chemical Sciences, University of L'Aquila, via Vetoio, 67100 Coppito L'Aquila, Italy
| | - C Puglia
- Department of Physics and Astronomy, Uppsala University, P.O. Box 516, SE-751 20 Uppsala, Sweden
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3
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Snezhkova O, Bischoff F, He Y, Wiengarten A, Chaudhary S, Johansson N, Schulte K, Knudsen J, Barth JV, Seufert K, Auwärter W, Schnadt J. Iron phthalocyanine on Cu(111): Coverage-dependent assembly and symmetry breaking, temperature-induced homocoupling, and modification of the adsorbate-surface interaction by annealing. J Chem Phys 2016; 144:094702. [PMID: 26957171 DOI: 10.1063/1.4942121] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
We have examined the geometric and electronic structures of iron phthalocyanine assemblies on a Cu(111) surface at different sub- to mono-layer coverages and the changes induced by thermal annealing at temperatures between 250 and 320 °C by scanning tunneling microscopy, x-ray photoelectron spectroscopy, and x-ray absorption spectroscopy. The symmetry breaking observed in scanning tunneling microscopy images is found to be coverage dependent and to persist upon annealing. Further, we find that annealing to temperatures between 300 and 320 °C leads to both desorption of iron phthalocyanine molecules from the surface and their agglomeration. We see clear evidence of temperature-induced homocoupling reactions of the iron phthalocyanine molecules following dehydrogenation of their isoindole rings, similar to what has been observed for related tetrapyrroles on transition metal surfaces. Finally, spectroscopy indicates a modified substrate-adsorbate interaction upon annealing with a shortened bond distance. This finding could potentially explain a changed reactivity of Cu-supported iron phthalocyanine in comparison to that of the pristine compound.
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Affiliation(s)
- Olesia Snezhkova
- Division of Synchrotron Radiation Research, Department of Physics, Lund University, P.O. Box 118, 221 00 Lund, Sweden
| | - Felix Bischoff
- Physik Department E20, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany
| | - Yuanqin He
- Physik Department E20, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany
| | - Alissa Wiengarten
- Physik Department E20, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany
| | - Shilpi Chaudhary
- Division of Synchrotron Radiation Research, Department of Physics, Lund University, P.O. Box 118, 221 00 Lund, Sweden
| | - Niclas Johansson
- Division of Synchrotron Radiation Research, Department of Physics, Lund University, P.O. Box 118, 221 00 Lund, Sweden
| | - Karina Schulte
- MAX IV Laboratory, Lund University, P.O. Box 118, 221 00 Lund, Sweden
| | - Jan Knudsen
- Division of Synchrotron Radiation Research, Department of Physics, Lund University, P.O. Box 118, 221 00 Lund, Sweden
| | - Johannes V Barth
- Physik Department E20, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany
| | - Knud Seufert
- Physik Department E20, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany
| | - Willi Auwärter
- Physik Department E20, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany
| | - Joachim Schnadt
- Division of Synchrotron Radiation Research, Department of Physics, Lund University, P.O. Box 118, 221 00 Lund, Sweden
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Lüder J, de Simone M, Totani R, Coreno M, Grazioli C, Sanyal B, Eriksson O, Brena B, Puglia C. The electronic characterization of biphenylene—Experimental and theoretical insights from core and valence level spectroscopy. J Chem Phys 2015; 142:074305. [DOI: 10.1063/1.4907723] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Akbari A, Hashemi J, Niskanen J, Huotari S, Hakala M. Identification of the dye adsorption modes in dye-sensitised solar cells with X-ray spectroscopy techniques: a computational study. Phys Chem Chem Phys 2015; 17:10849-55. [DOI: 10.1039/c4cp05980h] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
X-ray photoelectron spectroscopy of O 1s is shown to be the most reliable technique in assessing adsorption geometry of dye molecules in a dye-sensitised solar cell.
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Affiliation(s)
- Ali Akbari
- Department of Physics
- University of Helsinki
- Helsinki
- Finland
| | - Javad Hashemi
- Department of Physics
- University of Helsinki
- Helsinki
- Finland
| | | | - Simo Huotari
- Department of Physics
- University of Helsinki
- Helsinki
- Finland
| | - Mikko Hakala
- Department of Physics
- University of Helsinki
- Helsinki
- Finland
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Mehboob Alam M. Donor's position-specific channel interference in substituted biphenyl molecules. Phys Chem Chem Phys 2015; 17:17571-6. [DOI: 10.1039/c5cp02492g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Changing the relative positions of the donor group can reverse the nature of channel interference in donor–acceptor substituted biphenyls.
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Affiliation(s)
- Md. Mehboob Alam
- Laboratoire de Chimie Quantique
- Institut de Chimie
- CNRS/Université de Strasbourg
- Strasbourg 67000
- France
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7
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Kawerk E, Carniato S, Journel L, Marchenko T, Piancastelli MN, Žitnik M, Bučar K, Bohnic R, Kavčič M, Céolin D, Khoury A, Simon M. Resonant inelastic x-ray scattering on iso-C2H2Cl2 around the chlorine K-edge: Structural and dynamical aspects. J Chem Phys 2014; 141:144301. [DOI: 10.1063/1.4897251] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Elie Kawerk
- CNRS, UMR 7614, Laboratoire de Chimie Physique-Matière et Rayonnement, F-75005 Paris, France
- Sorbonne Universités, UPMC Université Paris 06, UMR 7614, Laboratoire de Chimie Physique-Matière et Rayonnement, F-75005 Paris, France
- Laboratoire de Physique Appliquée, Faculté des Sciences II, Université Libanaise, 90656 Jdeidet el Metn, Liban
- Dipartimento di Scienze Chimiche, Università di Trieste, Via L. Giorgieri 1, I-34127 Trieste, Italy
| | - Stéphane Carniato
- CNRS, UMR 7614, Laboratoire de Chimie Physique-Matière et Rayonnement, F-75005 Paris, France
- Sorbonne Universités, UPMC Université Paris 06, UMR 7614, Laboratoire de Chimie Physique-Matière et Rayonnement, F-75005 Paris, France
| | - Loïc Journel
- CNRS, UMR 7614, Laboratoire de Chimie Physique-Matière et Rayonnement, F-75005 Paris, France
- Sorbonne Universités, UPMC Université Paris 06, UMR 7614, Laboratoire de Chimie Physique-Matière et Rayonnement, F-75005 Paris, France
| | - Tatiana Marchenko
- CNRS, UMR 7614, Laboratoire de Chimie Physique-Matière et Rayonnement, F-75005 Paris, France
- Sorbonne Universités, UPMC Université Paris 06, UMR 7614, Laboratoire de Chimie Physique-Matière et Rayonnement, F-75005 Paris, France
| | - Maria Novella Piancastelli
- CNRS, UMR 7614, Laboratoire de Chimie Physique-Matière et Rayonnement, F-75005 Paris, France
- Sorbonne Universités, UPMC Université Paris 06, UMR 7614, Laboratoire de Chimie Physique-Matière et Rayonnement, F-75005 Paris, France
- Department of Physics and Astronomy, Uppsala University, P.O. Box 516, SE-751 20 Uppsala, Sweden
| | - Matjaž Žitnik
- Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
| | - Klemen Bučar
- Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
| | - Rok Bohnic
- Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
| | - Matjaž Kavčič
- Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
| | - Denis Céolin
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin, BP 48, F-91192 Gif-sur-Yvette Cedex, France
| | - Antonio Khoury
- Laboratoire de Physique Appliquée, Faculté des Sciences II, Université Libanaise, 90656 Jdeidet el Metn, Liban
| | - Marc Simon
- CNRS, UMR 7614, Laboratoire de Chimie Physique-Matière et Rayonnement, F-75005 Paris, France
- Sorbonne Universités, UPMC Université Paris 06, UMR 7614, Laboratoire de Chimie Physique-Matière et Rayonnement, F-75005 Paris, France
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8
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Fronzoni G, Baseggio O, Stener M, Hua W, Tian G, Luo Y, Apicella B, Alfé M, de Simone M, Kivimäki A, Coreno M. Vibrationally resolved high-resolution NEXAFS and XPS spectra of phenanthrene and coronene. J Chem Phys 2014; 141:044313. [DOI: 10.1063/1.4891221] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Giovanna Fronzoni
- Dipartimento di Scienze Chimiche e Farmaceutiche, Università di Trieste, Via L. Giorgieri 1, I-34127 Trieste, Italy
- Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali, INSTM, Unita’ di Trieste, I-34127 Trieste, Italy
| | - Oscar Baseggio
- Dipartimento di Scienze Chimiche e Farmaceutiche, Università di Trieste, Via L. Giorgieri 1, I-34127 Trieste, Italy
- Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali, INSTM, Unita’ di Trieste, I-34127 Trieste, Italy
| | - Mauro Stener
- Dipartimento di Scienze Chimiche e Farmaceutiche, Università di Trieste, Via L. Giorgieri 1, I-34127 Trieste, Italy
- Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali, INSTM, Unita’ di Trieste, I-34127 Trieste, Italy
| | - Weijie Hua
- Department of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology, S-106 91 Stockholm, Sweden
| | - Guangjun Tian
- Department of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology, S-106 91 Stockholm, Sweden
| | - Yi Luo
- Department of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology, S-106 91 Stockholm, Sweden
- National Synchrotron Radiation Laboratory and Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Barbara Apicella
- Istituto di Ricerche sulla Combustione, IRC-CNR, P.le Tecchio, 80, 80125 Napoli, Italy
| | - Michela Alfé
- Istituto di Ricerche sulla Combustione, IRC-CNR, P.le Tecchio, 80, 80125 Napoli, Italy
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9
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Zhang Y, Hua W, Bennett K, Mukamel S. Nonlinear Spectroscopy of Core and Valence Excitations Using Short X-Ray Pulses: Simulation Challenges. DENSITY-FUNCTIONAL METHODS FOR EXCITED STATES 2014; 368:273-345. [DOI: 10.1007/128_2014_618] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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10
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Hua W, Biggs JD, Zhang Y, Healion D, Ren H, Mukamel S. Multiple Core and Vibronic Coupling Effects in Attosecond Stimulated X-Ray Raman Spectroscopy (SXRS). J Chem Theory Comput 2013; 9:10.1021/ct400767g. [PMID: 24376391 PMCID: PMC3870907 DOI: 10.1021/ct400767g] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Attosecond Stimulated X-ray Raman Spectroscopy (SXRS) is a promising technique for investigating molecular electronic structure and photochemical processes with high spatial and temporal resolution. We present a theoretical study of SXRS from multiple core excitation sites of the same element. Two issues are addressed: interference between pathways contributing the signals from different sites; and how nuclear vibrations influence the signals. Taking furan as a model system, which contains two types of carbons Cα and Cβ, we performed time-dependent density functional theory calculations and computed the SXRS signals with two pulses tuned at the carbon K-edge. Our simulations demonstrate that the SXRS signal from the Cα and Cβ sites are non-additive, owing to the significant mixed contributions (Cα 1s excitations by the pump pulse followed by Cβ 1s excitations by the probe, or vice verse). Harmonic vibrations linearly coupled to the electronic transitions are incorporated using the cumulant expansion. The nuclei act as a bath for electronic transitions which accelerate the decay of time-domain signal. The frequency-domain spectrum is modified by a small red shift and high-resolution fine-structure features are introduced.
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Affiliation(s)
- Weijie Hua
- Department of Chemistry, University of California, Irvine, CA 92697-2025, United States
| | - Jason D. Biggs
- Department of Chemistry, University of California, Irvine, CA 92697-2025, United States
| | - Yu Zhang
- Department of Chemistry, University of California, Irvine, CA 92697-2025, United States
| | - Daniel Healion
- Department of Chemistry, University of California, Irvine, CA 92697-2025, United States
| | - Hao Ren
- Department of Chemistry, University of California, Irvine, CA 92697-2025, United States
| | - Shaul Mukamel
- Department of Chemistry, University of California, Irvine, CA 92697-2025, United States
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11
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Hua W, Tian G, Fronzoni G, Li X, Stener M, Luo Y. Fe L-Edge X-ray Absorption Spectra of Fe(II) Polypyridyl Spin Crossover Complexes from Time-Dependent Density Functional Theory. J Phys Chem A 2013; 117:14075-85. [DOI: 10.1021/jp408776p] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Weijie Hua
- Department
of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology, S-106 91 Stockholm, Sweden
| | - Guangjun Tian
- Department
of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology, S-106 91 Stockholm, Sweden
| | - Giovanna Fronzoni
- Dipartimento
di Scienze Chimiche e Farmaceutiche, Università di Trieste, Via L. Giorgieri
1, I-34127 Trieste, Italy
| | - Xin Li
- Department
of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology, S-106 91 Stockholm, Sweden
| | - Mauro Stener
- Dipartimento
di Scienze Chimiche e Farmaceutiche, Università di Trieste, Via L. Giorgieri
1, I-34127 Trieste, Italy
| | - Yi Luo
- Department
of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology, S-106 91 Stockholm, Sweden
- National Synchrotron
Radiation Laboratory and Hefei National Laboratory for Physical Sciences
at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, People’s Republic of China
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12
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Fukuda R, Ehara M. Electronic excited states and electronic spectra of biphenyl: a study using many-body wavefunction methods and density functional theories. Phys Chem Chem Phys 2013; 15:17426-34. [DOI: 10.1039/c3cp52636d] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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13
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Fatehi S, Schwartz CP, Saykally RJ, Prendergast D. Nuclear quantum effects in the structure and lineshapes of the N2 near-edge x-ray absorption fine structure spectrum. J Chem Phys 2010; 132:094302. [DOI: 10.1063/1.3324889] [Citation(s) in RCA: 13] [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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14
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Turchanin A, Käfer D, El-Desawy M, Wöll C, Witte G, Gölzhäuser A. Molecular mechanisms of electron-induced cross-linking in aromatic SAMs. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:7342-52. [PMID: 19485375 DOI: 10.1021/la803538z] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
When aromatic self-assembled monolayers (SAMs) are electron-irradiated, intermolecular cross-links are formed and the SAMs transform into carbon nanosheets with molecular thickness. These nanosheets have a very high mechanical stability and can withstand temperatures above 1000 K. In this report, we investigate the electron induced cross-linking of 1,1'-biphenyl-4-thiol (BPT) SAMs on gold by combining X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (NEXAFS), thermal desorption spectroscopy (TDS), and UV photoelectron spectroscopy (UPS). The experimental data were acquired as a function of electron dose and temperature and compared with quantum chemical calculations. Details of the intermolecular cross-linking, the microstructure of cross-linked films, and their structural transformations upon heating were obtained to derive a view of the mechanisms involved. Our analysis shows that room-temperature electron irradiation causes a lateral cross-linking via the formation of C-C linked phenyl species as well as a new sulfur species. The thermal stability of the BPT films increases with the electron dose and saturates at approximately 50 mC/cm2. Nevertheless, nonlinked fragments in the thermal desorption spectra indicate an incomplete cross-linking even at high doses, which can be attributed to steric reasons and quenching due to the reduced band gap of partially linked molecules. At temperatures above 800 K, all sulfur species are thermally desorbed, while the remaining film reveals an onset of carbonization.
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Affiliation(s)
- Andrey Turchanin
- Physics of Supramolecular Systems, University of Bielefeld, Germany.
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15
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Schwartz CP, Uejio JS, Saykally RJ, Prendergast D. On the importance of nuclear quantum motions in near edge x-ray absorption fine structure spectroscopy of molecules. J Chem Phys 2009; 130:184109. [DOI: 10.1063/1.3125509] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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16
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Uejio JS, Schwartz CP, Saykally RJ, Prendergast D. Effects of vibrational motion on core-level spectra of prototype organic molecules. Chem Phys Lett 2008. [DOI: 10.1016/j.cplett.2008.10.088] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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17
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Wang J, Cooper G, Tulumello D, Hitchcock AP. Inner Shell Excitation Spectroscopy of Biphenyl and Substituted Biphenyls: Probing Ring−Ring Delocalization. J Phys Chem A 2005; 109:10886-96. [PMID: 16331932 DOI: 10.1021/jp054693n] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Quantitative optical oscillator strength spectra for C 1s excitation and ionization of gas-phase biphenyl, decafluorobiphenyl, and 2,2'-bis(bromomethyl)-1,1'-biphenyl have been derived from electron energy loss spectroscopy recorded under electric dipole dominated conditions. The C 1s X-ray absorption spectrum of hexaphenylbenzene has been recorded in the solid state. The C 1s spectral features are interpreted with the aid of ab initio calculations for core excitation of benzene, biphenyl, hexafluorobenzene, and decafluorobiphenyl. A weak feature at 287.7 eV in biphenyl is identified as a C 1s --> pi(deloc) transition, characteristic of ring-ring delocalization. Its intensity and position are shown to be related to the average torsion angle and thus the extent of pi-pi-interaction between adjacent aromatic rings. The effects of perfluoro substitution on core excitation spectra are also characterized and discussed.
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Affiliation(s)
- Jian Wang
- Department of Chemistry, McMaster University, Hamilton, Ontario, Canada L8S 4M1
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