Theoretical studies on the characterization of classical and non-classical C68 isomers and their newly synthesized derivatives by spectroscopy

Abstract

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 unparalleled non-classical (NC) isomer C₁-C₆₈(NC3) and the chlorinated derivative C₁-C₆₈(NC3)Cl₂₈ with its partially hydrolyzed derivatives C₁-C₆₈(NC3)Cl₂₆(OH)₂ and C₁-C₆₈(NC3)Cl₂₅(OH)₃, along with the classical non-IPR (isolated pentagon rule) fullerene C_2v-^#6073C₆₈ and its metal carbide clusterfullerene Sc₂C₂@C₂-^#6073C₆₈ have been calculated at the density-functional-theory (DFT) level. The electronic structures and X-ray spectra of classical and non-classical fullerenes are undoubtedly distinguished from their counterparts, as are the substances that have undergone chlorination. The two derivatives produced in the partial hydrolysis of chloride C₁-C₆₈(NC3)Cl₂₈ also exhibit distinctive properties. The “fingerprint” in X-ray spectroscopy is capable of offering an effective tool for the identification of the aforementioned isomers, as evidenced by the reality that the XPS and NEXAFS spectra demonstrate isomer dependence. Ultraviolet-visible (UV-vis) absorption spectroscopy of Sc₂C₂@C₂-^#6073C₆₈ was carried out using time-dependent (TD) DFT calculations. The emulated results and the outcomes of the experiment coincide well. This study indicates how X-ray and UV-vis spectroscopy methods can provide valuable data to support researchers in exploring the electronic structure of fullerene materials and the identification of isomers in both further experimental and theoretical disciplines.