The Molecular and Electronic Structure of NdF₂^-/0

Area of Science:

• Inorganic Chemistry
• Quantum Chemistry
• Spectroscopy

Background:

• Understanding the electronic structure of f-element compounds is crucial for materials science.
• Neodymium difluoride (NdF2) and its anion (NdF2-) represent model systems for studying f-element bonding.

Purpose of the Study:

• To elucidate the molecular and electronic structures of NdF2- and NdF2.
• To investigate the photodetachment process of NdF2-.
• To compare the electronic structure of NdF2-/0 with its periodic analogue UF2-/0.

Main Methods:

• Anion photoelectron spectroscopy (aPES) was employed to measure the vertical detachment energy (VDE) of NdF2-.
• Quantum chemistry calculations, including relativistic multireference methods, were used to determine electronic states and molecular geometries.
• Geometry optimizations were performed for both the anion and neutral species.

Main Results:

• The experimental VDE of NdF2- was measured at 1.11 eV, closely matching the theoretical prediction of 1.106 eV.
• Both NdF2- and NdF2 adopt bent C2v structures.
• The ground state of NdF2- is determined to be 4A2 (4f36s2), and the neutral NdF2 is 5A2 (4f36s1).
• A dense manifold of low-lying neutral excited states was identified.
• Similarities in electronic structure, bonding, and geometry were observed between NdF2-/0 and UF2-/0.

Conclusions:

• The combination of aPES and relativistic multireference calculations is effective for studying the electronic structure of f-element molecules.
• The results provide fundamental insights into the nature of bonding in neodymium fluoride species.
• The comparison with UF2-/0 highlights periodic trends in f-element difluorides.