Intensities of hot bands in the dimol emissions of singlet molecular oxygen, O2(1Δg)

Abstract

The temperature dependence of the three dimol emissions of oxygen O₂(¹Δ_g) at 579, 634 and 703 nm has been studied between 295 and 1500 K with a discharge-flow–shock-tube apparatus. The intensity increases with temperature and concentration as expected for these bimolecular processes, but there is a further increase which is attributed to the appearance of overlapping hot-band emissions from vibrationally excited molecules of O₂(¹Δ_g). For the 703 nm emission there is an additional contribution from hot bands of O₂(¹Σ⁺_g).

The relative emissivities of the bands and the rate constants for the collisional emission reactions have been determined and are presented in table 4.

The values found appear to indicate that, for these simultaneous transitions from two colliding molecules, the intensities are governed by an electronic transition probability which changes rapidly with intermolecular distance.