Line frequency shift measurements by diode-laser spectroscopy for CH(3)D-Xe

Area of Science:

• Molecular Spectroscopy
• Quantum Chemistry
• Astrophysical Chemistry

Background:

• Understanding molecular line broadening is crucial for atmospheric remote sensing and astrophysical observations.
• Deuterium-labeled methane (12CH(3)D) is a molecule of interest in various chemical and physical studies.
• Pressure-induced spectral line parameters provide insights into intermolecular interactions.

Purpose of the Study:

• To experimentally determine the pressure-induced Xenon (Xe) shifting and broadening coefficients for specific lines of 12CH(3)D.
• To compare experimental data with theoretical predictions derived from a semiclassical model.
• To validate the accuracy of the Lennard-Jones (LJ) potential in describing Xe-12CH(3)D interactions.

Main Methods:

• Utilized a tunable diode-laser spectrometer for high-resolution spectral measurements.
• Measured Xe-broadened lines and pure 12CH(3)D lines at low pressure simultaneously.
• Employed a semiclassical model incorporating the atom-atom Lennard-Jones (LJ) potential for theoretical calculations.

Main Results:

• Successfully measured the pressure-induced Xe shifting and broadening coefficients for five lines of 12CH(3)D in the nu(3) band.
• Observed frequency shifts and line broadening effects due to Xenon pressure.
• Obtained quantitative data for spectral line parameters near 7.5 micrometers.

Conclusions:

• The study provides valuable experimental data on Xe-broadened spectral lines of 12CH(3)D.
• Experimental results offer a basis for evaluating the performance of theoretical models.
• The findings contribute to a better understanding of intermolecular forces and spectral line shapes.