Fluorescence and quenching of O2(1Δ<i>g</i>) and [O2(1Δ<i>g</i>)]2 in liquid oxygen

Abstract

Liquid oxygen, oxygen/nitrogen, and oxygen/argon mixtures were excited by 1.060 μ radiation from a Nd:glass laser. The fluorescence decay was monitored at 6340 Å, 7030 Å, 1.27 μ, and 1.58μ. The quenching rate coefficient of O2(a 1Δg) by O2(X 3Σg−) was found to be 1.0±0.1×10−18 cm3/sec at 77°K. The temperature variation between 77 and 322°K is consistent with 2.2×10−18 (T/300)1/2 cm3/sec. Quenching by N2 and argon was at least an order of magnitude slower. In every case the decay of [O2(1Δg)]2 was twice as fast as that of O2(1Δg) alone, indicating that even at liquid nitrogen temperature [O2(1Δg)]2 is in rapid collisional equilibrium with O2(1Δg).