Drift Velocities and Interactions of Negative Ions in Oxygen. II.O4−

The drift velocity and rates of formation of the $\mathrm{O}_4^{}{}_{}{}^{-}$ ion have been investigated in oxygen at 310 °K and pressures between 0.5 and 4 Torr. This paper reports the first determination of the rate of formation of the $\mathrm{O}_4^{}{}_{}{}^{-}$ ion. The rates for the forward and reverse reactions $\mathrm{O}_2^{}{}_{}{}^{-}+{\mathrm{O}}_2+{\mathrm{O}}_2\rightleftharpoons \mathrm{O}_4^{}{}_{}{}^{-}+{\mathrm{O}}_2$ were found to be 3×${10}^{31}$ cm${}_{}{}^6{}_{}{}^{}/\mathrm{s}\mathrm{e}\mathrm{c}$ and 2×${10}^{-14\mathrm{}}$ ${\mathrm{cm}}^3$/sec, respectively. The drift velocity of $\mathrm{O}_4^{}{}_{}{}^{-}$ is essentially identical to that of $\mathrm{O}_2^{}{}_{}{}^{-}$ with a low-field reduced mobility ($\mu N$) of 5.9×${10}^{19}$ ${\mathrm{}\left(\mathrm{V}\mathrm{cm}\sec \right)\mathrm{}}^{-1\mathrm{}}$. These measurements indicate that not only can $\mathrm{O}_4^{}{}_{}{}^{-}$ play an important role in experiments involving negative ions in oxygen, but also that any future attempts to model the negative-ion chemistry of the atmosphere must include the reactions of the $\mathrm{O}_4^{}{}_{}{}^{-}$ ion.