Infrared multiphoton-absorption-induced ion desorption from solid state C60 fullerene and anthracene

We have studied multiphoton-absorption-induced ionization of solid state organic molecules (ftillerene, anthracene and pyrene) by means of time-of-flight mass spectroscopy using an infrared free electron laser (IR-FEL). IR irradiation of the fullerene and anthracene solid films gives rise to desorption of ion species with significantly high translational energies (> 5000 K). The time of birth of the ion species extends to several micro seconds after firing off the FEL macro-pulse. No clear IR wavelength dependence of ionization yield was observed. Pyrene, a polycyclic aromatic hydrocarbon similar to anthracene, exhibits only melting and evaporation.