Valérie Vallet
@valevallet.bsky.social
63 followers 98 following 6 posts
CNRS researcher in theoretical and computational chemistry PhLAM institute @univlille.bsky.social
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valevallet.bsky.social
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...
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.
doi.org
Reposted by Valérie Vallet
gemarh.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
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valevallet.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
anttonrouget.bsky.social
Au moins 24 structures ont déjà été soutenues par «Périclès», le projet du milliardaire PE Sterin pour mettre l’extrême droite au pouvoir, révèle La Lettre. Dans le lot : le mouvement «Ethic» de Sophie de Menthon, les assos de l'essayiste Céline Pina ou de l'anthropologue Florence Bergeaud-Blackler.
Pierre-Édouard Stérin sort le carnet de chèques pour faire gagner la droite de la droite dans les têtes et dans les urnes - LA LETTRE
Alerte publiée le 30/01/25 à 17 h 58 - De Contribuables Associés au très droitier Institut de formation politique, en passant par le lobby patronal de Sophie de Menthon, le milliardaire catholique
www.lalettre.fr
Reposted by Valérie Vallet
bitsyperlman.bsky.social
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
benstemon.bsky.social
It’s official: all funding requests made on Tuesday by postdocs for their salaries have been unilaterally rejected by NSF.
Reposted by Valérie Vallet
prlogos.bsky.social
#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
Reposted by Valérie Vallet
prlogos.bsky.social
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.
Reposted by Valérie Vallet
carlbergstrom.com
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.