The emission bands of HO2 between 1·43 and 1·51 μm

Abstract

The ² A′ →² A″ electronic spectrum of HO₂ at 1·43 μm has been recorded at high resolution with a SISAM spectrometer. The analysis of the spectrum has yielded accurate molecular constants for the lowest vibrational level of the excited state. Emission is only observed from K′ ⩽ 2>; possible explanations for this phenomenon are discussed. Forbidden ΔK = 0 transitions are observed; the principal mechanism for their existence is believed to be a Renner-Teller interaction between the two electronic states. Vibrational hotbands of the type ² A′ (v ₁ v ₂ v ₃) →² A″(v ₁ v ₂ v ₃) are observed. New spectro-scopic information includes the three vibrational frequencies of the excited electronic state; the previous discrepancy in the value of ν₃ is explained. The O-H stretching overtone band ² A″(200) →² A″(000) at 1·51 μm has also been recorded and analysed.