Theoretical Studies on the Structural and Spectral Properties of Several Classical and Nonclassical C₇₈ Isomers and Its Novel Chlorinated Derivative C₇₈Cl₂₄

Abstract

X-ray photoelectron spectra (XPS), near-edge X-ray absorption fine structure spectra (NEXAFS), and X-ray emission spectroscopy (XES), as well as the ground-state electronic/geometrical structures about the significant classical isolated-pentagon rule (IPR) isomer D 3h -#24109C78, the non-IPR isomers C 2-#22010C78 and C 1-#23863C78, and the nonclassical isomer C 2-C78(NC2) with its chlorinated derivative C 2-C78(NC2)­Cl24, which are newly obtained in the experiment, have been calculated at the density functional theory (DFT) level. Significant differences have been observed in the electronic structure and the X-ray spectra. All X-ray spectra have shown strong isomer dependence; consequently, the “fingerprint” in X-ray spectra shows a very effective way to isolate the fullerene isomers above. As a result, this work indicates that X-ray spectroscopy can provide valuable identification for classical and nonclassical fullerenes as well as their derivatives on experimental and theoretical studies.

Structural and spectral properties of a non-classical C58 isomer and its fluorinated derivatives in theory

“… 75,76 Such observation again confirms the effective changes in the geometrical and electronic structures of the C 58 backbone after fluorination. Compared with the previous studies of C 54 , 36 C 60 , 34 C 72 , 35 C 74 , 37 C 78 , 38 and their chlorinated derivatives, the fluorides still have an obvious blue shift after fluorination. It is worth mentioning that the blue shift after fluorination is 0.2 eV more than that produced by chlorination.…”

“…32,33 The paper aim to explore the electronic structures of C 58 isomers and uorinated derivatives, and provide a valid way for isomer characterization and iden-tication because of X-ray spectra show strong isomer dependence in present study. [34][35][36][37][38] It is expected that the results of this research will provide a further theoretical support for the progress of experimental and theoretical researches in C 58 fullerene isomers and derivatives.…”

“…All of the above results are well consist with the previous theoretical conclusions of C 54 , 36 C 60 , 34 C 72 , 35 C 74 , 37 and C 78 . 38 …”

“…The similar blue shift exists in the NEXAFS spectra of fluorides in this work compared with that after chlorination in the previous studies of C 54 , 36 C 60 , 34 C 72 , 35 C 74 , 37 and C 78 . 38 Hence, the NEXAFS spectra can provide effective identification information for different isomers.…”

“…All of the above results are well consist with the previous theoretical conclusions of C 54 , 36 C 60 , 34 C 72 , 35 C 74 , 37 and C 78 . 38 The calculated C 1s XPS spectra of the two uorinated species compared with the corresponding C 58 backbone are presented in Fig. 4(a).…”