High resolution ro-vibrational analysis of molecules in doublet electronic states: theν1fundamental of chlorine dioxide (16O35Cl16O) in theX2B1electronic ground state

Oleg N. Ulenikov, Elena S. Bekhtereva, Olga V. Gromova, Martin Quack, Kirill B. Berezkin, Christian Sydow, Sigurd Bauerecker

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We report the spectrum of theν1fundamental of chlorine dioxide centered in the infrared atmospheric window at 945.592 cm−1measured with essentially Doppler limited resolution at an instrumental line width of 0.001 cm−1using the Zürich prototype ZP2001 Bruker IFS 125 HR Fourier transform infrared spectrometer. The ro-vibrational line analysis is carried out with an improved effective Hamiltonian and a newly developed computer code ROVDES for the ro-vibrational spectra of open-shell free radical molecules including spin-rotation interactions. Accurate values of rotational, centrifugal and spin-rotational parameters were determined for16O35Cl16O in the vibronic ground stateX2B1from more than 3500 ground state combination differences. The 7239 assigned transitions for theν1fundamental withNmax= 76 andKmaxa 26 provide a set of 32 accurate effective Hamiltonian parameters for theν1fundamental (v1v2v3) = (100) (21 rotational and centrifugal distortion parameters and 11 spin-rotational interaction parameters). This effective Hamiltonian (A- reduction andIr- representation) reproduces 1703 upper state energies from the experiment with a root-mean-square deviationdrms= 1.67 × 10−4cm−1and the 7239 transition wavenumbers withdrms= 3.45 × 10−4cm−1. Our results provide a considerable improvement over previous results with which we compare and should provide a benchmark for theoretical studies with applications to atmospheric spectroscopy and laser chemistry, which are discussed in relation to our spectra.

Original languageEnglish
Pages (from-to)4580-4596
Number of pages17
JournalPhysical Chemistry Chemical Physics
Issue number8
Publication statusPublished - 28 Feb 2021

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

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