Theoretical Study on the Structure and Spectral Properties of Several Classical C84 Isomers and Their Newly Synthesized Derivatives

Theoretical Study on the Structure and Spectral Characteristics of Three Boron-Doped Fullerene C27B Isomers and Their Newly Synthesized Uranium-Embedded Derivatives

The ground-state electronic/geometrical structures of the three C27B fullerene isomers and the corresponding parental carbon cage Td-#2C28, as well as the respective embedded derivatives U@C27B have been calculated at the density functional theory level. The three isomers of C27B are identified by theoretical simulations of X-ray photoelectron spectroscopy (XPS), near-edge X-ray absorption fine structure spectroscopy (NEXAFS). After boron atom doping, effective changes in electronic structure and simulated X-ray spectra are observed. Analysis of the interaction between U and fullerenes C27B indicates that this is a co-stabilizing effect resulting from the coexistence of ionic and covalent bonds. This study can contribute valuable information for further experimental and theoretical research on the freshly synthesized doped fullerenes and their derivatives through the combination of XPS and NEXAFS.

B-Doped Graphdiynes and Several of Their Corresponding Oxides: A Theoretical Study by X-ray Spectra

Boron doping can significantly improve the electronic structure and physical and chemical properties of graphdiyne (GDY), which also expands its application prospects in photoelectricity, catalysis, and biology. The accurate configurations characterization of B-doped graphdiyne (B-GDY) has not been achieved due to insufficient experimental and theoretical research. The current work involves the simulation of the geometries of 11 typical B-GDY and B-doped graphdiyne oxides [B(O)-GDY] as well as a pristine GDY, along with their X-ray photoelectron (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectra at the density functional theory (DFT) level. The boron and carbon spectra for various bonding types were theoretically imitated to assess the spectral contributions. Calculated outcomes indicate that there is a noticeable dependence of the NEXAFS spectra on the local structure. The simulated XPS spectra provide precise assignments and an extra supplement to the spectra peaks, in addition to the position and general peak forms of simulated spectral peaks matching the experimental spectra fairly well. The combination of XPS and NEXAFS spectra can give useful information for identifying typical B-GDY and B(O)-GDY molecules. This paper offers a comprehensive structure-spectrum relationship of B-GDY and its oxides as well as a further theoretical prediction and guidance for experimental synthesis, which is helpful to solve the challenging issue of identification of B-doped carbon-based materials.

Theoretic Study of Sulfur-Doped Graphdiynes by X-ray Spectroscopy

Sulfur-doped graphdiyne at different sites has a tremendous impact on its electronic structure and properties. Due to the large number of S-doping sites, there is no comprehensive and systematic experimental and theoretical study regarding the identification of S-doped graphdiyne configurations. In this paper, X-ray photoelectron (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectra as well as geometries of 10 sulfur-doped graphdiyne molecules have been simulated at the density functional theory (DFT) level. Different types of carbon spectra were theoretically modeled to analyze the contribution of the spectra. Calculated results show that the NEXAFS spectra exhibit a clear dependence on the local structure. The theoretically simulated XPS spectra are in good agreement with the experimental spectra. The XPS spectra combined with the NEXAFS spectra can provide effective information for identifying the 10 S-doped conformations. Our research results provide further theoretical prediction and guidance for the experimental synthesis of S-doped graphdiyne, which solves the difficult problem of identification of S-doped carbon-based materials.