Theoretical Study on the Structure and Spectral Properties of Several Classical and Non-Classical C 76 Isomers and Their Newly Synthesized Derivatives.

X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectra, as well as the ground-state electronic/geometrical structures of the newly discovered two non-classical isomers C 2 -C 76 (NC2) and C 1 -C 76 (NC3) with their derivatives C 2 -C 76 (NC2)(CF 3 ) 14 and C 1 -C 76 (NC3)Cl 24 , as well as the non-IPR(isolated pentagon rule) isomer C 1 - #17418 C 76 with its embedded metal fullerene U@C 1 - #17418 C 76 have been calculated at the density functional theory (DFT) level. The electronic structure after chlorination is significantly different in the simulated X-ray spectrum. Both XPS and NEXAFS spectra reflect obvious isomer dependence, indicating that the "fingerprint" in X-ray spectroscopy can provide an effective means for the identification of the above-mentioned fullerene isomers. Time-dependent DFT was used to simulate the ultraviolet-visible absorption spectrum of U@C 1 - #17418 C 76 . The calculated results are in good agreement with the experimental consequence. This work reveals that theoretically simulated X-ray and UV-vis spectroscopy techniques can provide valuable information to help researchers explore the electronic structure of fullerenes and the identification of isomers in future experimental and theoretical fields.