Theoretical Identification of the Six Stable C84 Isomers by IR, XPS, and NEXAFS Spectra.

Six stable C84 isomers satisfying isolated pentagon rule (IPR) have been theoretically identified by infrared (IR), X-ray photoelectron (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectra. The XPS and NEXAFS spectra at the K-edge for all nonequivalent carbon atoms were simulated by the density functional theory method. NEXAFS spectra show stronger dependence than IR and XPS spectra on the six C84 isomers, which can be properly used for isomer identification. Furthermore, spectral components of total spectra for carbon atoms in different local environment have been explored.