THE TRANSITION-PROBABILITY OF ELECTRON LOSS FROM ANIONS IN THE GAS-PHASE - THE LIFETIME OF O-2(.-)

The unimolecular primary chemical process, A - --> A + e-, is investigated from a theoretical and computational point of view. A "standard" procedure for calculating the lifetime of A- directly is proposed based on the quantum mechanical transition probability. Specific application of the standard procedure is made to electron loss from O2.-. The lifetime of O2.- (upsilon' = 4) calculated with the proposed method is 36 X 10(-12) s, in good agreement with experimental data. An improvement to the standard procedure yields the best theoretical estimate for the lifetime, 125 X 10- 12 s. The lifetimes of O2.- at higher vibrationally excited states are also calculated and agree well with those of previous calculations. The dependence of the calculated lifetime on the geometric and vibrational parameters of O2 and O2.- is discussed.