The VUV Absorption Spectra of SiF and SiF+

Area of Science:

• Molecular Spectroscopy
• Atomic and Molecular Physics
• Quantum Chemistry

Background:

• Understanding the electronic structure of small molecules like silicon tetrafluoride (SiF4) is crucial in various chemical and physical applications.
• Previous studies have explored SiF4, but detailed characterization of its ionic states and transitions remains an active area of research.

Purpose of the Study:

• To investigate the absorption spectrum of SiF4 under microwave discharge conditions.
• To identify new ionization energies and electronic states of the SiF+ ion.
• To characterize the A1Pi <-- X1Sigma+ transition of SiF+.

Main Methods:

• Recording the absorption spectrum of a microwave discharge (2450 MHz) in flowing helium with traces of SiF4.
• Utilizing the SA61 beam line of SUPERACO for spectral analysis.
• Employing high-resolution spectroscopy with a 35-foot Eagle spectrograph.

Main Results:

• Two new ionization energies were observed at 15.12 eV and 17.27 eV.
• These energies correspond to the A1Pi and B1Sigma+ electronic states of the SiF+ ion.
• The A1Pi <-- X1Sigma+ transition of SiF+ was identified for the first time.

Conclusions:

• The study successfully identified new electronic states of SiF+ and their corresponding ionization energies.
• The first identification of the A1Pi <-- X1Sigma+ transition provides valuable data for theoretical and experimental molecular spectroscopy.
• This research contributes to a deeper understanding of the electronic structure and spectroscopy of fluorosilanes.