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.