The interaction between nonmetal and metal atoms has attracted great interest in the development of organometallic compounds and their promising applications. In this study, we explored the interaction between boron and thorium atoms, based on the stable B₄₀Th coordination compound, by employing density functional theory calculations. We elucidated the stability and geometries of the B₄₀Th coordination compound and revealed the electron transfer from the metal atom Th to B₄₀, which is evidenced by the natural bond orbital calculations. This electron transfer is attributed to the electron-withdrawing character of the boron atom and results in clear electrostatic interaction. Additionally, bond critical analysis and bond order calculations show obvious covalent characters between the metal and nonmetal atoms. The IR spectrum was simulated to give detailed information to identify this targeted compound in future experiments. This study is expected to enhance the understanding of metal–nonmetal interactions and provides useful information for constructing new organometallic compounds based on actinium metal atoms.

The high radioactivity and toxicity of nuclear wastewater, significant contributors to environmental pollution, have drawn considerable attention from the scientific community. This research delves into the adsorption mechanism of actinide cations, namely, Pa-(V), U-(VI), Np-(V), and Pu-(VI), on carboxylated graphene oxide (GO). Specifically, we examined three distinct carboxylated functional groups situated on the graphene edges: -COOH, -O-COOH, and -NH-COOH. Utilizing density functional theory (DFT), we conducted a systematic investigation into the structures, bonding characteristics, and adsorption energies of Pa-(V), U-(VI), Np-(V), and Pu-(VI) when interacting with GO. Rigorous geometric analysis and resonant frequency calculations demonstrate that Pu-(VI) exhibits stronger bonding with GO than Pa-(V), U-(VI), and Np-(V) cations. Furthermore, analysis of adsorption energies shows that among the tested actinide cations, Pu-(VI) displays the highest affinity for GO, whereas U-(VI) exhibits the lowest. Concurrently, Np-(V) demonstrates a marginally higher affinity than Pa-(V), consistent with previous experiments. Electrostatic potential (ESP) and atomic charge analyses suggest that the -NH group acts as an electron donor toward adjacent -COOH groups, enhancing their electrostatic attraction for hydrated actinide cations. By elucidating interaction mechanisms at molecular scales, this research may pave the way for designing GO-based materials in radioactive wastewater treatment.

LaFe₁₂B₆ is a rare itinerant-electron metamagnet, and substitution of rare-earth elements can significantly influence its field-induced phase transition and magnetocaloric effects. However, how such elemental substitution modulates its magnetoelectrical transport properties remains unclear. Here, we report electrical transport measurements on La_1−xPr_xFe₁₂B₆ (x = 0.05, 0.15) compounds between 3 and 150 K in fields up to 90 kOe using the four-wire method on characterized polycrystals containing 9.5 and 3.8 wt.% Fe₂B, respectively. Samples were thermally reset and demagnetized prior to each isothermal test. At 3 K, magnetoresistance (MR) reproduces the following magnetization features: two abrupt MR drops at 41 and 67 kOe for x = 0.05. Below the first critical field, the MR becomes positive (+20% for x = 0.05, +5% for x = 0.15) and then drops abruptly. The steps broaden and merge into a smooth response as the temperature rises. The largest negative MR values measured, −78% (x = 0.05, 40 K) and −68% (x = 0.15, 70 K), lie close to the corresponding magnetic transitions. The incomplete resistivity recovery observed after field removal—most pronounced at low temperature for both compositions and vanishing near 120 K—reveals a kinetically arrested transformation. By combining magneto-transport with magnetization measurements, the giant negative magnetoresistance (up to −78%) of La_1−xPr_xFe₁₂B₆ closely tracks the stepwise metamagnetic transition, via field-suppressed spin-disorder scattering, with the effect extending above T_C for the Pr-richer composition.