Absolute line intensities of HONO and DONO in the far-infrared and re-determination of the energy difference between the trans- and cis-species of nitrous acid

The ν4 bands at 11 µm: linelists for the Trans- and Cis- conformer forms of nitrous acid (HONO) in the 2019 version of the GEISA database

“…We have to adopt a reliable value for ECis-Trans since this entity, which was determined during several experimental [20,21,22,23,24] and ab initio [25,26,27,28,29] investigations, is not firmly established. At the present time we are unable to decide which value of ECis-Trans is the correct one.…”

“…Among these, various experimental values range from 107 to 225 cm -1 . The most recent study by Sironneau et al [24] which has led to: S ECis-Trans =10726cm -1 Ref. [24] Eq.…”

“…The most recent study by Sironneau et al [24] which has led to: S ECis-Trans =10726cm -1 Ref. [24] Eq. ( 5)…”

“…This was done in the literature (Ref. [24] and references therein) by performing line intensity measurements for Trans-HONO and Cis-HONO rotational transitions at high resolution in the far infrared or Thz region, and by comparing the observed absorptions to the theoretical computed intensities.…”

Simultaneous measurements of atmospheric HONO and NO2 via absorption spectroscopy using tunable mid-infrared continuous-wave quantum cascade lasers

“…We Deviation of the sample from the temperature at which our effective line-strengths were determined will result in a change in the cis to trans ratio. The effective line-strengths can be corrected knowing the cis-trans energy barrier, for which there is a large discrepancy amongst reported values [24][25][26][27][28]. In practice, a constant sample temperature is well maintained by heating the inlet, tubing, the optical table and its protective cover.…”