DOUBLY IONIZED STATES OF HEXAFLUOROBENZENE STUDIED BY HIGH-RESOLUTIONAUGER-ELECTRON AND DOUBLE-CHARGE-TRANSFER SPECTROSCOPIES

Double-charge-transfer (DCT) spectroscopy has been used to measure the double-ionization energies of C6F6. OH+ and F+ projectile ions with t ranslational energy of 6 keV, which tend to populate triplet states in the dication, were used. From the position of peaks in the resultant DCT spectra, C6F6 double ionization energies of 26.3 +/- 0.5, 28.4 +/- 0.5, 29.2 +/- 0.5, 32.2 +/- 0.5, 35.0 +/- 1 and 40.0 +/- 1 eV were de termined. The photon-induced Auger electron spectra of C6F6 were recor ded. The Auger electron spectra are dominated by transitions to final states of singlet symmetry. Ten distinct structures are observed in th e C ls Auger electron spectrum centred at double ionization energies o f 26.63 +/- 0.1, 30.37 +/- 0.1, 34.68 +/- 0.1, 36.26 +/- 0.1, 37.84 +/ - 0.1, 39.19 +/- 0.2, 42.73 +/- 0.3, 46.51 +/- 0.1. 49.20 +/- 0.1 and 50.40 +/- 0.2 eV. Five structures were observed in the F ls outer-oute r spectrum, centred at double ionization energies of 42.20 +/- 0.1, 46 .14 +/-0.1, 48.61 +/- 0.1, 52.53 +/- 0.1 and 56.9 +/- 0.1. Additional structures are observed in the outer-inner and inner-inner spectrum. A comparison has been made between the results from the present work an d those obtained in a recent coincidence study (K. Ibrahim, P. Lablanq uie, M-J. Hubin-Franskin, J. Delwiche, M. Furan, 1. Nenner, D. Hagan a nd J. H. D. Eland, J. Chem. Phys., 1992, 96, 1981). Green's function c alculations have been performed to assist the interpretation of the sp ectra.