Observations on O(1D→3P) and O2(b 1Σg+ →X 3Σg−) following O2 photodissociation

Abstract

Time‐resolved studies have been made on the energy transfer process O(1 D)+O2→O(3 P)+O2(b 1Σ g +) v . O(1 D) was generated by O2photodissociation at ?1600 Å, using an H2 laser, and observed by its emission at 6300 Å. Only the v=0 and 1 levels are produced in O2(b 1Σ g +) by energy transfer, in the ratio k 1/k 0=0.7. The quantum efficiency of converting O(1 D) electronic energy into O2(b 1Σ g +) is 0.77±0.2, in agreement with the most recent determination. O2(b 1Σ g +) v=1 is quenched very rapidly by O2, with a rate coefficient of 2.2×10−11 cm3 molec−1 s−1. This is almost six orders of magnitude faster than O2 quenching of O2(b 1Σ g +) v=0 and accounts for the weakness of emission from the v=1 level in the terrestrial airglow.