Formation of gas-phase metal fluorides in reactions of fluorinated fullerenes at activated metal surfaces.

A comparative investigation into the chemical reactions of a series of fluorinated fullerenes (C 60 F 18 , C 60 F 36 and C 60 F 48 ) with a variety of activated metal surfaces is reported. New ways of generating intense beams of metal fluoride anions are demonstrated: either in reactions of fluorinated fullerene vapours with hot W and Mo metal surfaces in a plasma ion source or by laser desorption/ionisation (LDI) of solid fluorinated fullerenes from various metal substrates (Al, Fe, Cu, Pt, W). In both cases, the resulting metal fluorides and their anions are formed in the highest oxidation state, yielding molybdenum and tungsten hexafluoride anions (plasma ion source), aluminium and iron tetrafluoride anions, and copper trifluoride anions (LDI). No reactions were observed with Pt and W in LDI. The reactivity of the metals towards fluorination correlates with their positions in the metal activity series. Relative yields of bare metal cations are dictated by their ionisation energy. The yield of metal fluoride anions is strongly dependent on the fluorine content of the fluorofullerenes. [ABSTRACT FROM AUTHOR]