First observation of [Pu₆(OH)₄O₄]¹²⁺ cluster during the hydrolytic formation of PuO₂ nanoparticles using H/D kinetic isotope effect

Abstract

New insights are provided about the formation mechanism of PuO2 nanoparticles (NPs) by investigating an unprecedented kinetic isotope effect observed during their hydrolytic synthesis in H2O or D2O and attributed...

Ultrasonically controlled synthesis of UO2+xcolloidal nanoparticles

“…55,73 It is worth noting that an analogous mechanism has been recently suggested for Pu( iv ). 74 U 4+ ⇋ U(OH) 3+ → M → UO 2(NP) …”

Investigation of the Plutonium(IV) Interactions with Two Variants of the EF-Hand Ca-Binding Site I of Calmodulin

“…77 Actually, in the visible spectra recorded with CaMWT at pH 6, the intense band at 456 nm followed by a shoulder at 475 nm and the double band at 659 and 686 nm were similar to the features identified for these hexanuclear Pu(IV) clusters. 39,75,76 DOTA, acetate, and glycine clusters present similar shells around Pu, two oxygen shells at 2.19 to 2.29 Å (two or four oxygen atoms, respectively) and at 2.36 to 2.42 Å (four, six, or seven oxygen atoms, respectively). The two shells of Pu(IV) are identical with four Pu(IV) in the axial plane at 3.76 to 3.77 Å and one Pu(IV) in the equatorial plane at 5.31 to 5.35 Å.…”

“…34,41,42 It is important to note that the first step in the mechanisms of formation of Pu(IV) colloids, characterized by an absorbance at λ = 615 nm in visible spectroscopy, consists of the formation of a hexanuclear core of Pu [Pu 6 (OH) 4 O 4 ] 12+ . 39 It is possible to stabilize the core with ligands and stop the evolution of this cluster toward a Pu(IV) colloid.…”

“…Pu­(IV) is strongly hydrolyzed above pH 1 in the absence of any complexing agent . Neutralizing the acidity of the Pu solutions with bases results in multiple forms of plutonium, hydroxo, mono- and poly-nuclear, colloids, and clusters. − The solubility and precipitation point of the Pu­(OH) 4 form has been determined at pH = 1.22 with a solubility product constant of Pu­(OH) 4 pK = 56.3 . Another species, PuO 2 , can take a great diversity of forms. , Multiple structures have been determined with Pu–O bond distances from 2.20 to 2.44 Å and Pu–Pu distances between 3.79 and 3.90 Å.…”

“…Another species, PuO 2 , can take a great diversity of forms. , Multiple structures have been determined with Pu–O bond distances from 2.20 to 2.44 Å and Pu–Pu distances between 3.79 and 3.90 Å. In particular, the PuO 2 solid reference from oxalate conversion has a Pu–Pu distance at 3.81 Å. ,, It is important to note that the first step in the mechanisms of formation of Pu­(IV) colloids, characterized by an absorbance at λ = 615 nm in visible spectroscopy, consists of the formation of a hexanuclear core of Pu [Pu 6 (OH) 4 O 4 ] 12+ . It is possible to stabilize the core with ligands and stop the evolution of this cluster toward a Pu­(IV) colloid.…”