The threshold photoelectron spectrum of CF4 up to 60.5 eV has been recorded using synchrotron radiation and a penetrating-field electron spectrometer of high resolution. Our results confirm the broad spectral features of the X 2T1, A2T2 and B̃ 2E state bands of CF4+ reported previously with He I PES. The influence of autoionizing super-excited states of CF4 has been observed as an extension of the high-energy tail of the B 2E state, as a structured band in the energy region between the B 2E and C̃ 2T2 states, and as additional vibrational structure extending the D̃ 2A1 state band. Improved spectra of the C̃ 2T2 and D̃ 2A1 states have been obtained as a consequence of the high resolution of this study. The overall electronic state band profiles observed here up to about 26eV agree with a recently published low-resolution threshold photoelectron spectrum of CF4 [Creasey et al., Chem. Phys., 174 (1993) 441]. Between 26 and 60.5 eV a continuum-like background was observed with some broad-band features superimposed on it. One broad peak, centered on 40.3 eV, is tentatively assigned to the formation of the Ẽ 2T2 and F̃ 2A1 states of CF4+, but the formation of the double-charged ion, CF42+, may also be involved.
|Number of pages||9|
|Journal||Journal of Electron Spectroscopy and Related Phenomena|
|Publication status||Published - 10 Nov 1994|