Millimeter- and Submillimeter-Wave Spectrum of Methylene Fluoride-d(2)

Area of Science:

• Molecular spectroscopy
• Quantum chemistry
• Spectroscopic analysis of deuterated compounds

Background:

• Methylene fluoride (CH2F2) is a molecule of interest in atmospheric and chemical research.
• Deuterated isotopologues, such as CD(2)F(2), provide unique insights into molecular structure and dynamics.
• High-resolution spectroscopy is crucial for precise determination of molecular parameters.

Purpose of the Study:

• To investigate the millimeter- and submillimeter-wave spectrum of methylene fluoride-d(2) (CD(2)F(2)).
• To assign rotational transitions in the ground and v(4)=1 vibrational states.
• To refine molecular constants, including rotational and centrifugal distortion parameters.

Main Methods:

• Observation of millimeter- and submillimeter-wave spectra using a frequency-modulated spectrometer.
• Assignment of over 400 rotational transitions in the ground state and over 200 in the v(4)=1 state.
• Simultaneous least-squares fitting of spectral lines with microwave data using Watson's Hamiltonians.

Main Results:

• Successfully assigned numerous rotational transitions for CD(2)F(2) in both ground and excited vibrational states.
• Obtained improved values for rotational and quartic centrifugal distortion constants.
• Determined, for the first time, sextic distortion constants for both the ground and v(4)=1 states.

Conclusions:

• The study provides a comprehensive spectroscopic characterization of CD(2)F(2).
• The determined molecular constants enhance our understanding of the molecule's structure and dynamics.
• This data is valuable for future theoretical and experimental studies of fluorinated compounds.