State-dependent electron delocalization dynamics at the solute-solvent interface: soft-x-ray absorption spectroscopy...

Area of Science:

• Atomic and Molecular Physics
• X-ray Spectroscopy
• Computational Chemistry

Background:

• X-ray fluorescence yield (FY) spectra of transition metals can be distorted compared to transmission spectra.
• Nonradiative decay pathways are known to influence these spectral features.

Purpose of the Study:

• To elucidate the origin of spectral distortions in L-edge FY spectra of transition-metal aqueous solutions.
• To quantify the role of electron delocalization in these distortions.

Main Methods:

• Utilized partial and inverse partial fluorescence yields (PIXFY) on a microjet.
• Performed multireference ab initio electronic structure calculations.
• Compared spectra from Fe2+, Fe3+, and Co2+ aqueous solutions.

Main Results:

• Demonstrated that nonradiative decay channels cause spectral distortions.
• Quantified electron delocalization within the d-orbital manifold as a key factor.
• Showed state-dependent delocalization effects across different iron and cobalt oxidation states.

Conclusions:

• Nonradiative decay significantly impacts L-edge FY spectra.
• Electron delocalization in d orbitals is a primary cause of observed spectral distortions.
• The findings provide a fundamental understanding of electronic structure effects in transition-metal solutions.