Fragment ion yields from CF alpha Cl4-alpha in the Cl L-shell, the CK-shell and the FK-shell excitation regions

Fragment ions from CFalphaCl4-alpha (alpha=1-3) have been measured in the s oft X-ray region using monochromatized synchrotron radiation and a time-of- flight mass spectrometer. The atomic chlorine ion exhibits the highest yiel d at most photon energies. Following Cl 2p photoionization, C-Cl bonds are broken frequently, but the process where only the C-F bond is cleaved does not occur, yielding no production of CFalpha-1Cl4-alpha+. The reverse pheno menon happens at the F 1s photoionization; the rupture of one C-Cl bond doe s not take place. These findings, site-specific fragmentation, are ascribed to the characteristics of Auger transitions creating valence holes in diff erent molecular orbitals. (C) 1999 Elsevier Science B.V. All rights reserve d.