Perfluorinated Phthalocyanines on Cu 110 and Cu 110 2 x 1 O The Special Role of the Central Cobalt Atom

Interface properties of CoPcF16 on Cu 110 and Cu 110 2 1 O were investigated by X ray photoemission spectroscopy XPS , ultraviolet photoemission spectroscopy UPS , X ray absorption spectroscopy XAS , and scanning tunneling microscopy STM . The results are compared to FePcF16 on Cu 110 2 1 O. A charge transfer from both substrates to the central Co ion of CoPcF16 is observed. Unlike to FePcF16 and related molecules, the strong interaction between CoPcF16 molecules of the first layer and the Cu 110 substrate is only partially suppressed by oxygen termination. The special nature of the electronic structure of the Co ion in Co phthalocyanines is discussed. The analysis of the fluorine Auger parameter enables the discussion of initial and final state effects of core level binding energy shifts in photoemission. A bidirectional charge transfer also involving the macrocycle of CoPcF16 molecules is conclude