Valérie Vallet

Journal of the American Chemical Society The purple membrane from Halobacterium salinarum archaea can unidirectionally transfer charge carriers in response to incident photons, even after separation from living cells. Upon integration with semiconductor nanoparticles, this isolated membrane forms a photosynthetic biohybrid system capable of abiotically and efficiently converting dinitrogen into ammonia under ambient conditions. The cover concept was developed by the authors to visualize this light-driven abiotic nitrogen fixation pathway. An initial sketch was generated using ChatGPT’s DALL·E tool and was subsequently refined and finalized using Adobe Photoshop. View the article.

On JACS cover with the ANL Heavy Element group: Phenanthroline bends neptunyl into its most distorted shape ever—while plutonium resists and flips redox. Actinyl chemistry, rewritten. @jacs.acspublications.org #myACScover pubs.acs.org/toc/jacsat/1...

Reactions of Np(VI) and Pu(VI) with Phenanthroline Result in Bending the [NpVIO2]2+ Unit and a Reduced Pu(V) Species Despite decades of actinyl chemistry, genuinely bent actinyl structures remain rare beyond uranium. We report the first crystallographic characterization of a bent neptunyl(VI) complex, NpO2Cl2(phen)2, along with a linear plutonyl species that, unexpectedly, adopts the +V oxidation state. Coordination of two 1,10-phenanthroline ligands to NpO22+ enforces pronounced bending of the Oyl–Np–Oyl unit to 162° through steric clashes with the axial phenathroline ligand, representing the sharpest angle reported for any neptunyl(VI) complex. In contrast, synthesis with PuO22+ produces a reduced linear Pu(V) species, PuO2Cl(phen)2, underscoring the redox lability and the reluctance of plutonium to distort. Raman and IR spectra yield the first experimental stretching and interaction force constants for plutonyl(V). Comparison with values for plutonyl(VI) and bent and linear uranyl(VI) and neptunyl(VI) compounds shows that reduction perturbs the actinyl bond more than bending within one oxidation state. Electrochemical and spectroscopic studies clarify phenanthroline binding to Pu(VI) and the system’s reactivity. Quantum chemical calculations indicate that bending is energetically favored in the U–Np–Pu series, but the stabilization energy decreases as the actinide atomic number increases. NBO and QTAIM analyses reveal systematic trends: increasing 5f occupancy and decreasing An–Oyl bond covalency from U to Pu. These results demonstrate that ligand-induced bending in neptunyl(VI) species is not only electronically feasible but also synthetically achievable, though plutonyl(VI) is constrained by redox reactivity. This work expands the frontier of nonlinear actinyl chemistry and illuminates how structure, oxidation state, and electronic configuration interrelate across the actinyl series.

New bent neptunyl(VI) and plutonyl(V) chemistry in press! With @aspg.bsky.social at @univlille.bsky.social, David D. Schnaars, Emily R. Mikeska, Richard Wilson @Argonne National Laboratory U.S. Department of Energy (DOE)

doi.org/10.1021/jacs...

Congrats @gemarh.bsky.social as it made it to the cover of Inorganic Chemistry !

U4+ Speciation in Acidic Aqueous Solution: Insights from UV–Vis, EXAFS, XANES, and Quantum-Statistical Simulations This theoretical study investigates the UV–vis absorption properties of U4+-containing aqueous solutions and their relationship with the nature of aqua-complexes present at varying acidic levels. High...

U4+ Speciation in Acidic Aqueous Solution: Insights from UV–Vis, EXAFS, XANES, and Quantum-Statistical Simulations pubs.acs.org/doi/10.1021/...
Nice work part of G. Raposo-Hernández PhD, with E. Sanchez-Marcos, R. Pappalardo @unisevilla.bsky.social and F. Réal at PhLAM institute

U4+ Speciation in Acidic Aqueous Solution: Insights from UV–Vis, EXAFS, XANES, and Quantum-Statistical Simulations This theoretical study investigates the UV–vis absorption properties of U4+-containing aqueous solutions and their relationship with the nature of aqua-complexes present at varying acidic levels. High...

doi.org/10.1021/acs....
Unravelling UV–vis spectra of U4+-containing aqueous solutions and their relationship with the nature of complexes present at different pH levels. Selected as Featured article in Inorg. Chem. and a cornerstone of
@gemarh.bsky.social PhD at @unisevilla.bsky.social

🧵 Hilo: ¿Qué hacen los iones pesados como el plutonio o el uranio cuando los disuelves en agua? ¿Y por qué eso importa?
#HiloTesis
‪@filarramendi.bsky.social @unisevilla.bsky.social @crueuniversidades.bsky.social
‪‬

Chaque pays a son premier de cordée… Musk de l’autre côté de l’atlantique et PE Sterin en France… Les parts d’ombre grandissent

I'm very sad that "I have a paper on this" continues

Funding delays of > 30 days lead to, after 5 years:

- 40% increase in scientists exiting US labor force (constrained among those born in the US)
- 20% decrease in wages
- Burden is born by postdocs, grad students, and staff

#VeilleESR #ESR #keylabs
Le moratoire (temps de négociations avec les bureaucraties universitaires avant annonce le 12 mars) a été annoncé par Petit le lundi 27 janvier. Deux jours après, les nouveaux directeurs d'unités étaient accueillis au siège du CNRS par Petit, contredisant le moratoire.
Récit

Tiens, un autre truc marrant. Le bouquin d'Alain Aspect co-écrit par une plume n'est pas si mal: il raconte comment il a été improductif pendant 10 ans, comment son statut protecteur lui a permis d'explorer des territoires inconnus dans le temps long.
Le contraire exact de ce qu'il défend ici où là.

I don’t have a definitive source on this yet but it looks like NSF review panels have been canceled.

Sixty-some years ago, Eisenhower transformed higher education because he viewed a science education gap as the single greatest threat to national security.

This is absolutely an act of sabotage.