Valence ionic states and dissociative photoionization of CH3CFCl2 with synchrotron radiation

Valence ionic states and dissociative photoionization of CH3CFCl2 in 11–19 eV are investigated with threshold photoelectron and photoionization mass spectrometry (PIMS). Valence ionic states are assigned on comparison of vertical ionization energies determined in the threshold photoelectron spectrum with theoretically predicted values. Major fragments CH3CFCl+, CH2CCl+, and CH2CF+ were observed with their respective appearance energies 11.33, 13.71, and 14.18 eV, but CH3CFCl2+ was absent. A mechanism for CH3CFCl2 to form CH3CFCl++Cl is proposed. At greater ionization energies, H migration followed by HX elimination of CH3CFCl+ to form CH2CCl++HF or CH2CF++HCl takes place.