Excited states of perfluorinated oligo( p-phenylene) by inner-shell excitation

Abstract

Ion time-of-flight (TOF) mass spectra and near-edge X-ray absorption fine structure (NEXAFS) spectra of perfluorinated oligo( p-phenylene) (PF-8P) films near fluorine (F) and carbon (C) K-edges were observed. In ion TOF mass spectra near F and C K-edges, F +, CF + and CF 3 + were intensely observed. It indicates that C–C bonds of phenyl ring as well as C–F bonds are broken by irradiation of photons near F and C K-edges. Partial ion yield (PIY) spectra of PF-8P show clear hν dependence near F and C K-edges. Especially, near F K-edge, the PIY spectra of F + increases remarkably at hν=689.2 eV, which corresponds to the lowest peak in NEXAFS. The lowest peak in the NEXAFS near fluorine K-edge is assigned to the transition from F1s to σ(C–F) *. Furthermore, from the analysis of PIY spectra of PF-8P near carbon K-edge, the peak at hν=289.5 eV is ascribed to the transition from C1s to σ(C–F) *.