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Characterizing Far-infrared Laser Emissions and the Measurement of Their Frequencies
Published on: December 18, 2015
The Far Infrared Spectrum of HOCl: Line Positions and Intensities
Journal of Molecular Spectroscopy
|December 16, 1998
Summary
High-resolution far infrared spectroscopy of hypochlorous acid (HOCl) revealed precise rotational and centrifugal distortion constants for HO35Cl and HO37Cl ground states. Rotational corrections to the transition moment were also determined.
Area of Science:
- Molecular spectroscopy
- Quantum chemistry
Background:
- Hypochlorous acid (HOCl) is a key molecule in atmospheric chemistry.
- Understanding its spectral properties is crucial for atmospheric modeling and reaction mechanism studies.
Purpose of the Study:
- To record and analyze the high-resolution far infrared spectrum of HOCl.
- To determine precise molecular constants for the ground and excited vibrational states of HOCl isotopomers.
- To investigate vibrational-rotational interactions and determine properties of dark vibrational states.
Main Methods:
- Fourier transform spectroscopy in the 20-360 cm-1 range.
- Least-squares fitting of spectral lines using a Watson-type Hamiltonian.
- Analysis of relative line intensities to determine transition moment corrections.
Main Results:
- Precise rotational and centrifugal distortion constants for ground states of HO35Cl and HO37Cl.
- Determination of rotational corrections to the b-component of the permanent transition moment.
- Refitting of nu1, nu2, and nu3 vibrational bands, including high Ka values for the (001) state.
- Identification of Coriolis-type perturbations between (010)/(100) and (002)/(030) states, enabling determination of dark state band centers.
Conclusions:
- The study provides highly accurate spectroscopic parameters for HOCl.
- New insights into vibrational-rotational interactions and dark state properties were obtained.
- The results enhance the understanding of HOCl molecular structure and dynamics.
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