BOND-DISSOCIATION ENERGIES OF F-2(-) AND HF2- - A GAS-PHASE EXPERIMENTAL AND G2 THEORETICAL-STUDY

The bond energies in F-2(-) and HF2- have been determined using energy-resolved collision-induced dissociation in a flowing afterglow-triple quadrupole instrument. The quantity D-0(F-2(-)) is measured to be 27.9 +/- 1.6 kcal/mol. This can be used to derive EA(F-2) = 3.01 +/- 0.07 eV, which is in good agreement with literature values. The bond energy in bifluoride, DH298(FH-F-), is found to be 45.8 +/- 1.6 kcal/mol. This is significantly higher than the value determined from fluoride transfer equilibrium measurements (38.6 +/- 2.0 kcal/mol) but is in good agreement with the results from recent theoretical studies. Ab initio calculations of these quantities using the G2 method have been performed, which are found to be in excellent agreement with the experimental results.