Study of excited states of fluorinated copper phthalocyanine by inner shell excitation

Near edge X-ray absorption fine structure (NEXAFS) spectra of hexadecafluoro copper phthalocyanine (FCuPc) films (thickness of 50 Å) on MoS2 substrates were observed near the carbon (C) and fluorine (F) K-edges. From the analysis of the dependence of C and F K-edge NEXAFS spectra on the photon incidence angle (α), the average molecular tilt angle was determined to be 30◦. The lowest and second lowest peaks in the F K-edge NEXAFS were assigned to the transition to ∗. In the ion time-of-flight mass spectra of FCuPc excited by photons near the F K-edge, F+, CF+, and CF3+ ions were mainly observed. These results indicate that C–C bonds as well as C–F bonds are broken by the photon irradiation. From the analysis of the partial ion yield spectra of F+ and CF+ near the F K-edge, the lowest and second lowest peaks in the F K-edge NEXAFS spectra could be assigned to transitions to (C–F)∗ and (C–C)∗, respectively. © 2004 Elsevier B.V. All rights reserved.