Emission Spectroscopy and Ab Initio Calculations on IrN

Area of Science:

• Molecular Spectroscopy
• Quantum Chemistry
• Atomic Physics

Background:

• Iridium Nitride (IrN) is a diatomic molecule with complex electronic structure.
• Understanding IrN's electronic states is crucial for theoretical chemistry and materials science.
• Previous studies have assigned some electronic states, but further characterization is needed.

Purpose of the Study:

• To record and analyze the emission spectrum of IrN in the near-infrared region.
• To assign observed bands to a specific electronic transition.
• To determine molecular constants for the newly identified electronic state and validate theoretical predictions.

Main Methods:

• Fourier transform spectroscopy was employed to record the emission spectrum of IrN.
• IrN molecules were generated in an Iridium (Ir) hollow cathode lamp using a Neon/Nitrogen (N2) gas mixture.
• Rotational analysis of observed bands was performed to extract molecular constants.

Main Results:

• A new a(3)Pi-X(1)Sigma(+) electronic transition was identified in the 7500-9200 cm(-1) region.
• The 0-0 bands of the a(3)Pi(0)-X(1)Sigma(+) and a(3)Pi(1)-X(1)Sigma(+) subbands were assigned near 9175 and 8841 cm(-1).
• Accurate molecular constants for the a(3)Pi state were determined, including vibrational and rotational parameters, and electron configuration was discussed.

Conclusions:

• The experimental findings confirm the assignment of the a(3)Pi-X(1)Sigma(+) transition in IrN.
• Ab initio calculations support the experimental results and previous state assignments.
• The study provides valuable spectroscopic data for IrN, enhancing the understanding of its electronic properties.