Mass Distribution of Laser-Generated CnFm^- Cluster Ions

From laser ablating teflon sample in a high vacuum,various cluster ions C_nF_m^- C_nH^- and C_n^- have produced on a home-made instrument. The statistical distribution model was applied to correlate the mass distribution with their structural configuration and stability. Based on the analysis,Geometry of several series of cluster ions was suggested. Anong them,C_nF and C_nF₃^- are believed to have the linear chain configuration, the fluorine atom or CF3 group locates on the end of the C- C chain. C_nF_n^- may be the planar ring,and each carbon atom in the ring is bonded with a fluorine atom. Several "magic number", such as C7F- and C5F4-, are distinguished in the mass spectrum.