Associative-detachment reactions of O⁻ and O₂⁻ by O₂(¹Δ_g)

Abstract

The flowing afterglow technique has been used to study the electron detachment reactions OZ(lAg) + 02--f 2 0 2 + e and 02('Ag) + 0--f O3 + e The rates of these reactions are sufficiently fast to make them important processes in D region ionospheric chemistry.

Penning detachment from atomic clusters

“…These cross-sections are roughly an order-ofmagnitude larger than the corresponding geometrical cross section, R C 2 , which are also shown in the figure. The crosssections for Na 7 Ϫ are smaller than for Na 19 Ϫ . Therefore, the fact that two partial waves (lϭ0,2) are dominant in the first case, while only one (lϭ1) is dominant in the second case does not have a significant influence.…”

“…5 and will be shown below, due to the long-range nature of the Penning detachment process, the dipole-dipole term of the multipolar expansion of 1/r 12 is responsible for most of the relevant couplings of the process. Since the ejected electrons initially occupy the 1p and 2s orbitals for Na 7 Ϫ and Na 19 Ϫ , respectively, electrons will be mostly ejected into continuum orbitals with lϭ0 and 2 ͑Na 7 Ϫ ), and lϭ1 (Na 19 Ϫ ). Higher angular momenta lead to a redistribution of the final state population but barely affect the value of the total crosssection ͑see Ref.…”

“…Nevertheless it has gone nearly unstudied until recently. 7,8 Consistent with the large cross-sections, the detachment process is dominated by energy exchange when the distances between colliding partners is very large, so that the collision itself produces a minimal perturbation of the acceptor.…”

The solar flare of August 18, 1979: Incoherent scatter radar data and photochemical model comparisons

“…(See Phelps, 1969. ) However, k 2 is described as uncertain within a range of (+900%, -90%) (Fehsenfeld et al, 1969). We found that we could improve the agreement between the computed and measured peak n e by increasing the assumed value of k 2 from 2 x 10~1 0 cm 3 /s to 1 x 10~9.…”

Two Challenges for Experimenters

“…The first reported instance of detachment of an electron from a negative ion by collision with an excited species 7 was not really Penning detachment, although closely related to it. This was the observation of associative detachment of electrons from O − and O 2 − by collision with excited oxygen molecules, O 2 ( 1 Δ g ) to form ozone, O 3 .…”