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Hyperfine-resolved rotational spectroscopy of HCNH
The Journal of Chemical Physics
|February 16, 2024
Summary
This study refines spectroscopic parameters for the molecular ion protonated hydrogen cyanide (HCNH+) using double-resonance spectroscopy. Hyperfine splittings were resolved, improving measurements of the nitrogen quadrupole coupling constant.
Area of Science:
- Molecular Spectroscopy
- Astrochemistry
- Quantum Chemistry
Background:
- Protonated hydrogen cyanide (HCNH+) is a key molecule in interstellar chemistry.
- Accurate spectroscopic data is crucial for identifying HCNH+ in astronomical observations.
- Previous studies provided limited resolution for hyperfine structures.
Purpose of the Study:
- To revisit the rotational spectrum of HCNH+.
- To achieve higher resolution for hyperfine splittings.
- To refine spectroscopic parameters, particularly the quadrupole coupling constant.
Main Methods:
- Double-resonance spectroscopy in a cryogenic ion trap.
- Measurement of six rotational transitions between 74 and 445 GHz.
- Resolution of hyperfine splittings due to the 14N nucleus.
Main Results:
- Resolved hyperfine splittings for transitions up to J = 4 ← 3.
- Refined spectroscopic parameters for HCNH+.
- Improved determination of the quadrupole coupling constant (eQq).
Conclusions:
- The study provides more precise spectroscopic data for HCNH+.
- Enhanced understanding of the 14N nuclear quadrupole interaction.
- This data will aid in the detection and characterization of HCNH+ in interstellar environments.
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