Theoretical identification of C34 isomers by XPS and NEXAFS spectra

Theoretical identification of buckyonion fullerene C20@C60 isomers by XPS and NEXAFS spectroscopy

The C 1s X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy of two buckyonion fullerene C₂₀@C₆₀ isomers were theoretically simulated by density functional theory (DFT) method. In this paper, we mainly investigated the relationship between spectroscopy and structure and obtained the spectral dependence on the structures with different symmetries. Our results showed that both XPS and NEXAFS spectra exhibited remarkable dependence on the molecular structures, thus these two spectroscopic techniques could be adopted to identify the two C₂₀@C₆₀ isomers effectively. Additionally, we found that the building block approach could not predict the spectra for C₂₀@C₆₀ isomers due to the strong interaction between the two layer cages. Finally, we studied the decompositions of the total spectra from carbon atoms in different local environments to analyse the origins of the main features.

Identification of Four C40 Isomers by Means of a Theoretical XPS/NEXAFS Spectra Study

XPS and NEXAFS spectra of four stable C₄₀ isomers [29( C₂), 31( C _s), 38( D₂), and 39( D_{5 d})] have been investigated theoretically. We combined density functional theory and the full core hole potential method to simulate C 1s XPS and NEXAFS spectra for nonequivalent carbon atoms of four stable C₄₀ fullerene isomers. The NEXAFS showed obvious dependence on the four C₄₀ isomers, and XPS spectra are distinct for all four isomers, which can be employed to identify the four stable structures of C₄₀. Furthermore, the individual components of the spectra according to different categories have been investigated, and the relationship between the spectra and the local structures of C atoms was also explored.

Theoretical Identification of the Six Stable C84 Isomers by IR, XPS, and NEXAFS Spectra

Six stable C₈₄ isomers satisfying isolated pentagon rule (IPR) have been theoretically identified by infrared (IR), X-ray photoelectron (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectra. The XPS and NEXAFS spectra at the K-edge for all nonequivalent carbon atoms were simulated by the density functional theory method. NEXAFS spectra show stronger dependence than IR and XPS spectra on the six C₈₄ isomers, which can be properly used for isomer identification. Furthermore, spectral components of total spectra for carbon atoms in different local environment have been explored.

Theoretical identification of seven C80 fullerene isomers by XPS and NEXAFS spectroscopy

The molecular geometries and C1s NEXAFS spectra of seven IPR-satisfying isomers of fullerene C₈₀.