Core Excitations of Biphenyl

Minkov, I. M.; Gel’mukhanov, Faris; Ågren, Hans; Friedlein, Rainer; Suess, C.; Salaneck, W. R.

doi:10.1021/jp045447z

Cited by 23 publications

(24 citation statements)

References 43 publications

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“…In fact the two peaks are also characterized by a clearly different line profile: symmetric for the film and asymmetric for the gas phase. As already shown in our previous work 21 and similarly to biphenyl 38 and naphthalene, 39 the asymmetry of the gas phase line is ascribed to intramolecular vibrations, which give rise to an asymmetric tail. In the film the situation is different, since many of the intramolecular vibration modes become frustrated.…”

Section: Resultssupporting

confidence: 73%

Electronic structure investigation of biphenylene films

Totani

Grazioli

Zhang

et al. 2017

The Journal of Chemical Physics

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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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Section: Resultssupporting

confidence: 73%

Electronic structure investigation of biphenylene films

Totani

Grazioli

Zhang

et al. 2017

The Journal of Chemical Physics

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“…For molecules like naphthalene and biphenyl, comparable shifts in the 1s core levels have also been found for the carbon atoms connecting the two benzene-like rings. 27,28 After the fitting procedure including the skew parameter described above, the main experimental features could be reproduced.…”

Section: Resultsmentioning

confidence: 99%

“…In this energy range, there are four eigenstates, which correspond to the four experimental peaks A to D, besides the small shoulders, which are due to vibrations. 27,28 Peak A, HOMO, has main contributions from the C α and the C γ atoms. Peak B, e.g., HOMO-1, is at 8.9 eV and has main contributions from the C α and the C β peaks.…”

Section: Resultsmentioning

confidence: 99%

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The electronic characterization of biphenylene—Experimental and theoretical insights from core and valence level spectroscopy

Lüder

Simone²,

Totani

et al. 2015

The Journal of Chemical Physics

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In this paper, we provide detailed insights into the electronic structure of the gas phase biphenylene molecule through core and valence spectroscopy. By comparing results of X-ray Photoelectron Spectroscopy (XPS) measurements with ΔSCF core-hole calculations in the framework of Density Functional Theory (DFT), we could decompose the characteristic contributions to the total spectra and assign them to non-equivalent carbon atoms. As a difference with similar molecules like biphenyl and naphthalene, an influence of the localized orbitals on the relative XPS shifts was found. The valence spectrum probed by photoelectron spectroscopy at a photon energy of 50 eV in conjunction with hybrid DFT calculations revealed the effects of the localization on the electronic states. Using the transition potential approach to simulate the X-ray absorption spectroscopy measurements, similar contributions from the non-equivalent carbon atoms were determined from the total spectrum, for which the slightly shifted individual components can explain the observed asymmetric features.

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“…More detailed approaches calculate Franck-Condon factors based on a vibrational eigenmode analysis in the ground and excited states. These factors are used to modulate a single electronic transition and help to reproduce asymmetric lineshapes associated with accompanying transitions to excited vibrational modes [9,22,23]. However, the Franck-Condon approximation ignores the impact of nuclear motion on the electronic transition amplitude.…”

Section: Pacs Numbers: Unknownmentioning

confidence: 99%

Effects of vibrational motion on core-level spectra of prototype organic molecules

Uejio

Schwartz

Saykally

2008

Chemical Physics Letters

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A computational approach is presented for prediction and interpretation of core-level spectra of complex molecules. Applications are presented for several isolated organic molecules, sampling a range of chemical bonding and structural motifs. Comparison with gas phase measurements indicate that spectral lineshapes are accurately reproduced both above and below the ionization potential, without resort to ad hoc broadening. Agreement with experiment is significantly improved upon inclusion of vibrations via molecular dynamics sampling. We isolate and characterize spectral features due to particular electronic transitions enabled by vibrations, noting that even zero-point motion is sufficient in some cases. PACS numbers: UnknownWhen applied to molecular systems, core level spectroscopies are powerful probes of both occupied and unoccupied electronic states, uniquely revealing intimate details of both intra-and inter-molecular interactions [1]. Methods involving x-ray absorption (XAS, NEXAFS, XANES) or x-ray photo-electron spectroscopy (XPS) are increasingly being applied to complex molecular systems, including nucleotides, peptides and large organic molecules [2]. However, a major limitation of this technology is the fact that extraction of molecular information from these experiments often depends explicitly on comparisons with theoretical calculations, which are extremely challenging to perform at experimental accuracy. In this Letter, we describe the extension of a recently developed method for predicting core-level spectra of condensed phases [3] to isolated organic molecules -pyrrole, s-triazine, pyrrolidine and glycine -which demonstrates qualitative improvements over existing methods [4][5][6] in comparison with experiment and provides new insights into the origins of particular spectral features in terms of coupling of electronic and vibrational degrees of freedom.The challenges for simulating gas phase core-level spectra are maintaining accuracy in the following areas: (1) description of the core-hole excited state; (2) representation of both bound excitonic states below the ionization potential (IP) and resonance states in the continuum above the IP; and (3) inclusion of vibrational effects, either due to experiments being performed near room temperature, or from intrinsic zero-point motion.Density functional theory (DFT) [7,8] has proved accurate in reproducing the excitation energies associated with core-level spectra via total energy differences (socalled ∆SCF or ∆KS) [9]. Accordingly, we model the lowest energy core-level excited state self-consistently using a full core-hole and excited electron (XCH) [3]. This is particularly important for molecular systems, where screening of the core-hole excitation is greatly enhanced by the presence of the excited electron, which can be strongly bound to the core-hole in the lowest energy excited state. In contrast, for non-molecular condensed phases, such as covalent and ionic crystalline solids, the inherent dielectric screening of the valence charge density o...

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Core Excitations of Biphenyl

Cited by 23 publications

References 43 publications

Electronic structure investigation of biphenylene films

Electronic structure investigation of biphenylene films

The electronic characterization of biphenylene—Experimental and theoretical insights from core and valence level spectroscopy

Effects of vibrational motion on core-level spectra of prototype organic molecules

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