Fourier Transform Emission Spectroscopy of CuCl

Area of Science:

• Molecular Spectroscopy
• Computational Chemistry
• Quantum Chemistry

Background:

• Copper(I) chloride (CuCl) is a diatomic molecule with complex electronic structure.
• Accurate spectroscopic data is crucial for understanding molecular properties and chemical bonding.

Purpose of the Study:

• To experimentally observe and analyze the electronic spectra of CuCl.
• To revise the electronic state assignments of CuCl based on theoretical calculations.
• To obtain improved spectroscopic constants for the ground and excited states of CuCl.

Main Methods:

• High-resolution electronic spectroscopy using a Bruker IFS 120 HR Fourier transform spectrometer (FTS).
• Spectroscopic measurements were also performed using an FTS coupled with the McMath-Pierce Solar Telescope.
• Ab initio quantum chemical calculations were employed to support spectral assignment and analysis.

Main Results:

• Observed and measured various electronic transition bands of CuCl in the 18,000–25,000 cm⁻¹ region.
• Revised assignments for several electronic states, including a(3)Σ⁺, b(3)Π, A(1)Π, and B(1)Σ⁺, relative to the X(1)Σ⁺ ground state.
• Obtained refined spectroscopic constants for both excited and ground electronic states of CuCl.

Conclusions:

• The study provides a more accurate understanding of the electronic states and transitions in CuCl.
• Revised assignments and improved constants enhance the predictive power for CuCl spectroscopy.
• This work contributes valuable data for theoretical and experimental studies of metal halide molecules.