DOUBLE-IONIZATION ENERGIES TO GROUND AND ELECTRONICALLY EXCITED SINGLET AND TRIPLET-STATES OF CCL4(2+), CCL3F2+, CCL2F2(2+) AND CCLF3(2+)

Double charge transfer spectroscopy has been used to measure singlet and triplet electronic-state energies of CCl24+, CCl3F2+, CCl2F22+ and CClF23+ ions. Because of spin conservation, singlet states were populated when using H+ as the projectile ion and triplet states when using F+. Also, double-ionization energies to ground singlet and triplet states were calculated with second-order Moller-Plesset perturbation theory. The calculated energies are in resonable to good agreement with those measured. Some of the energies have been measured previously, and the corresponding data from the present investigation are in good agreement with them. The singlet-state energies for the last three title ions have been measured for the first time in the present investigation, and the higher-lying triplet-state energies of all the ions have been measured more accurately using the F+ projectile ion.