Core excitations of naphthalene: Vibrational structure versus chemical shifts

Royal Institute of Technology, S-106 91 Stockholm, Sweden.
The Journal of Chemical Physics (Impact Factor: 2.95). 10/2004; 121(12):5733-9. DOI: 10.1063/1.1784450
Source: PubMed


High-resolution x-ray photoelectron emission (XPS) and near-edge x-ray absorption fine structure (NEXAFS) spectra of naphthalene are analyzed in terms of the initial state chemical shifts and the vibrational fine structure of the excitations. Carbon atoms located at peripheral sites experience only a small chemical shift and exhibit rather similar charge-vibrational coupling, while the atoms in the bridging positions differ substantially. In the XPS spectra, C-H stretching modes provide important contributions to the overall shape of the spectrum. In contrast, the NEXAFS spectrum contains only vibrational progressions from particular C-C stretching modes. The accuracy of ab initio calculations of absolute electronic transition energies is discussed in the context of minute chemical shifts, the vibrational fine structure, and the state multiplicity.

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    • "The XAS results should therefore be considered to be representative for the terrace NDCA adsorbates only. The asymmetric low-energy peak in the X-ray absorption spectrum in Fig. 7 at around 285 eV is attributed to excitations from the naphthalene C 1s levels to the LUMO [27], while the higher energy peak at around 288 eV stems primarily from excitations Figure 7 C 1s X-ray absorption spectra for the same non-annealed submonolayer NDCA/Ag(110) preparation as in Fig. 6(b). An intensity offset was applied to the spectra for reasons of presentation . "
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    • "Besides the peak of adventitious carbon at 284.8 eV, the peak at 286.3 eV is assigned to ether bonding (C ⁎ –O–C) [8], indicating the presence of residue solvent, THF, on the surface of the particles. In addition, a small amount of naphthalene remaining on the surface is verified by the peak at 289.6 eV, which is close to the datum reported previously [9]. The peak at 287.9 eV is ascribed to C ⁎ fO which might derive from absorption of CO 2 in air. "
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