Structure and spin of the low- and high-spin states of Fe(phen) studied by x-ray scattering and emission spectroscopy.

The structure and spin of photoexcited Fe(phen) in water are examined by x-ray scattering and x-ray emission spectroscopy with 100 ps time resolution. Excitation of the low-spin (LS) ground state (GS) to the charge transfer state MLCT leads to the formation of a high-spin (HS) state that returns to the GS in 725 ps. Density functional theory (DFT) predicts a Fe-N bond elongation in HS by 0.

On the origin of low-valent uranium oxidation state.

The significant interest in actinide bonding has recently focused on novel compounds with exotic oxidation states. However, the difficulty in obtaining relevant high-quality experimental data, particularly for low-valent actinide compounds, prevents a deeper understanding of 5f systems. Here we show X-ray absorption near-edge structure (XANES) measurements in the high-energy resolution fluorescence detection (HERFD) mode at the uranium M edge for the U and U halides, namely UX and UX (X = F, Cl, Br, I).

: a density-functional-theory-based structural toolkit to analyze EXAFS spectra.

This article presents a Python-based program, , to regress theoretical extended X-ray absorption fine structure (EXAFS) spectra calculated from density functional theory structure models against experimental EXAFS spectra. To showcase its application, Ce-doped fluorapatite [Ca(PO)F] is revisited as a representative of a material difficult to analyze by conventional multi-shell least-squares fitting of EXAFS spectra. The software is open source and publicly available.

Nonadiabatic Charge Transfer within Photoexcited Nickel Porphyrins.

Metalloporphyrins with open d-shell ions can drive biochemical energy cycles. However, their utilization in photoconversion is hampered by rapid deactivation. Mapping the relaxation pathways is essential for elaborating strategies that can favorably alter the charge dynamics through chemical design and photoexcitation conditions.

Orbital Magnetic Moment and Single-Ion Magnetic Anisotropy of the = 1/2 K[Fe(CN)] Compound: A Case Where the Orbital Magnetic Moment Dominates the Spin Magnetic Moment.

The potassium hexacyanoferrate(III), K[Fe(CN)], is known for its exceptional magnetic anisotropy among the 3d transition metal series. The Fe(III) ions are in the = 1/2 low spin state imposed by the strong crystal field of the cyanido ligands. A large orbital magnetic moment is expected from previous publications.