Photoelectron spectrum of PrO(-)

Area of Science:

• Physical Chemistry
• Quantum Chemistry
• Spectroscopy

Background:

• Understanding the electronic structure of metal oxides is crucial for catalysis and materials science.
• Previous studies on Cerium Oxide anion (CeO-) provide a comparative basis for Praseodymium Oxide anion (PrO-) investigations.
• The electronic states of PrO are complex due to the involvement of f-electrons.

Purpose of the Study:

• To characterize the electronic and vibrational states of neutral Praseodymium Oxide (PrO) using photoelectron spectroscopy.
• To determine the adiabatic electron affinity of PrO.
• To investigate potential shake-up transitions and unobserved electronic states of PrO.

Main Methods:

• Photoelectron (PE) spectroscopy was employed to study the PrO- anion.
• Analysis of vibrational progressions and doublets in the PE spectrum.
• Density functional theory (DFT) calculations were performed for theoretical support.

Main Results:

• A vibrational progression with a splitting of 210 ± 30 cm(-1) was observed and assigned to transitions to Ω = 3.5 and 4.5 neutral states.
• The adiabatic electron affinity of PrO was determined to be 0.96 ± 0.01 eV.
• Features approximately 1 eV above the ground state were assigned to shake-up transitions to excited neutral states, including the 4f(2) [(3)H4] 5d superconfiguration.

Conclusions:

• The photoelectron spectrum of PrO- provides detailed insights into the electronic structure of neutral PrO.
• The study successfully determined the adiabatic electron affinity and identified key electronic transitions.
• The term energy of the previously unobserved 4f(2) [(3)H4] σ6s Ω = 2.5 neutral state was estimated at 1840 ± 110 cm(-1).