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Pu3Br is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Pu is bonded in a square co-planar geometry to four equivalent Br atoms. All Pu–Br bond lengths are 3.38 Å. Br is bonded to twelve equivalent Pu atoms to form a mixture of corner and face-sharing BrPu12 cuboctahedra.
PuY3 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Pu is bonded to twelve equivalent Y atoms to form PuY12 cuboctahedra that share corners with six equivalent PuY12 cuboctahedra, corners with twelve equivalent YY8Pu4 cuboctahedra, edges with eighteen equivalent YY8Pu4 cuboctahedra, faces with eight equivalent PuY12 cuboctahedra, and faces with twelve equivalent YY8Pu4 cuboctahedra. There are six shorter (3.43 Å) and six longer (3.60 Å) Pu–Y bond lengths. Y is bonded to four equivalent Pu and eight equivalent Y atoms to form YY8Pu4 cuboctahedra that share corners with four equivalent PuY12 cuboctahedra, corners with fourteen equivalent YY8Pu4 cuboctahedra, edges with six equivalent PuY12 cuboctahedra, edges with twelve equivalent YY8Pu4 cuboctahedra, faces with four equivalent PuY12 cuboctahedra, and faces with sixteen equivalent YY8Pu4 cuboctahedra. There are a spread of Y–Y bond distances ranging from 3.45–3.64 Å.
PuAu2Ag is Heusler structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Pu is bonded in a body-centered cubic geometry to eight equivalent Au atoms. All Pu–Au bond lengths are 3.04 Å. Au is bonded in a body-centered cubic geometry to four equivalent Pu and four equivalent Ag atoms. All Au–Ag bond lengths are 3.04 Å. Ag is bonded in a distorted body-centered cubic geometry to eight equivalent Au atoms.
PuHg2Cd is Heusler structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Pu is bonded in a body-centered cubic geometry to eight equivalent Hg atoms. All Pu–Hg bond lengths are 3.17 Å. Hg is bonded in a body-centered cubic geometry to four equivalent Pu and four equivalent Cd atoms. All Hg–Cd bond lengths are 3.17 Å. Cd is bonded in a distorted body-centered cubic geometry to eight equivalent Hg atoms.
PuAl3 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Pu is bonded to twelve equivalent Al atoms to form a mixture of face and corner-sharing PuAl12 cuboctahedra. There are six shorter (3.03 Å) and six longer (3.09 Å) Pu–Al bond lengths. Al is bonded in a 10-coordinate geometry to four equivalent Pu and six equivalent Al atoms. There are two shorter (2.89 Å) and four longer (2.90 Å) Al–Al bond lengths.
Pu4Sb3 crystallizes in the cubic I-43d space group. The structure is three-dimensional. Pu is bonded to six equivalent Sb atoms to form a mixture of distorted edge, face, and corner-sharing PuSb6 octahedra. The corner-sharing octahedra tilt angles range from 16–50°. There are three shorter (3.16 Å) and three longer (3.28 Å) Pu–Sb bond lengths. Sb is bonded to eight equivalent Pu atoms to form a mixture of distorted edge, face, and corner-sharing SbPu8 hexagonal bipyramids.
PuOs3B2 crystallizes in the hexagonal P6/mmm space group. The structure is three-dimensional. Pu3+ is bonded to two equivalent Pu3+ and twelve equivalent Os1- atoms to form distorted PuPu2Os12 cuboctahedra that share corners with fourteen equivalent PuPu2Os12 cuboctahedra, edges with six equivalent PuPu2Os12 cuboctahedra, edges with twelve equivalent BOs6 pentagonal pyramids, faces with two equivalent PuPu2Os12 cuboctahedra, and faces with six equivalent BOs6 pentagonal pyramids. Both Pu–Pu bond lengths are 2.97 Å. All Pu–Os bond lengths are 3.17 Å. Os1- is bonded in a distorted square co-planar geometry to four equivalent Pu3+ and four equivalent B atoms. All Os–B bond lengths are 2.19 Å. B is bonded to six equivalent Os1- atoms to form distorted BOs6 pentagonal pyramids that share corners with six equivalent BOs6 pentagonal pyramids, edges with six equivalent PuPu2Os12 cuboctahedra, edges with three equivalent BOs6 pentagonal pyramids, faces with three equivalent PuPu2Os12 cuboctahedra, and faces with two equivalent BOs6 pentagonal pyramids.
Pu4Rh is Iron carbide-like structured and crystallizes in the cubic Fd-3m space group. The structure is zero-dimensional and consists of eight Pu4Rh clusters. Pu is bonded in a single-bond geometry to one Rh atom. The Pu–Rh bond length is 2.57 Å. Rh is bonded in a tetrahedral geometry to four equivalent Pu atoms.
PuCl is Tungsten Carbide structured and crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. Pu is bonded in a 6-coordinate geometry to six equivalent Cl atoms. All Pu–Cl bond lengths are 3.04 Å. Cl is bonded in a 6-coordinate geometry to six equivalent Pu atoms.
Na3Pu crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Na is bonded in a 2-coordinate geometry to six equivalent Na and four equivalent Pu atoms. There are four shorter (3.54 Å) and two longer (3.79 Å) Na–Na bond lengths. There are two shorter (3.64 Å) and two longer (3.93 Å) Na–Pu bond lengths. Pu is bonded to twelve equivalent Na atoms to form a mixture of corner and face-sharing PuNa12 cuboctahedra.
NaPuF4 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are three inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six F1- atoms. There are a spread of Na–F bond distances ranging from 2.31–2.64 Å. In the second Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six F1- atoms. There are a spread of Na–F bond distances ranging from 2.30–2.54 Å. In the third Na1+ site, Na1+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of Na–F bond distances ranging from 2.37–2.92 Å. There are three inequivalent Pu3+ sites. In the first Pu3+ site, Pu3+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of Pu–F bond distances ranging from 2.39–2.47 Å. In the second Pu3+ site, Pu3+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of Pu–F bond distances ranging from 2.40–2.49 Å. In the third Pu3+ site, Pu3+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of Pu–F bond distances ranging from 2.40–2.47 Å. There are twelve inequivalent F1- sites. In the first F1- site, F1- is bonded to two Na1+ and two Pu3+ atoms to form a mixture of corner and edge-sharing FNa2Pu2 tetrahedra. In the second F1- site, F1- is bonded in a 4-coordinate geometry to two Na1+ and two Pu3+ atoms. In the third F1- site, F1- is bonded to two Na1+ and two Pu3+ atoms to form a mixture of distorted corner and edge-sharing FNa2Pu2 tetrahedra. In the fourth F1- site, F1- is bonded in a 4-coordinate geometry to two Na1+ and two Pu3+ atoms. In the fifth F1- site, F1- is bonded in a 3-coordinate geometry to two Na1+ and two Pu3+ atoms. In the sixth F1- site, F1- is bonded to two Na1+ and two Pu3+ atoms to form a mixture of distorted corner and edge-sharing FNa2Pu2 tetrahedra. In the seventh F1- site, F1- is bonded to two Na1+ and two Pu3+ atoms to form a mixture of distorted corner and edge-sharing FNa2Pu2 tetrahedra. In the eighth F1- site, F1- is bonded to one Na1+ and three Pu3+ atoms to form a mixture of distorted corner and edge-sharing FNaPu3 tetrahedra. In the ninth F1- site, F1- is bonded to one Na1+ and three Pu3+ atoms to form a mixture of distorted corner and edge-sharing FNaPu3 tetrahedra. In the tenth F1- site, F1- is bonded to two Na1+ and two Pu3+ atoms to form a mixture of distorted corner and edge-sharing FNa2Pu2 tetrahedra. In the eleventh F1- site, F1- is bonded to two Na1+ and two Pu3+ atoms to form a mixture of distorted corner and edge-sharing FNa2Pu2 tetrahedra. In the twelfth F1- site, F1- is bonded to one Na1+ and three Pu3+ atoms to form a mixture of distorted corner and edge-sharing FNaPu3 tetrahedra.
Pu4Ni is Iron carbide-like structured and crystallizes in the cubic Fd-3m space group. The structure is zero-dimensional and consists of eight Pu4Ni clusters. Pu is bonded in a single-bond geometry to one Ni atom. The Pu–Ni bond length is 2.52 Å. Ni is bonded in a tetrahedral geometry to four equivalent Pu atoms.
Abstract Understanding the chemistry of the inert actinide oxo bond in actinyl ions AnO 2 2+ is important for controlling actinide behavior in the environment, during separations, and in nuclear waste (An=U, Np, Pu). The thioether calixarene TC4A (4‐ tert ‐butyltetrathiacalix[4]arene) binds equatorially to the actinyl cation forming a conical pocket that differentiates the two trans‐ oxo groups. The ‘ate’ complexes, [A] 2 [UO 2 (TC4A)] (A=[Li(DME) 2 ], HNEt 3 ) and [HNEt 3 ] 2 [AnO 2 (TC4A)] (An=U, Np, Pu), enable selective oxo chemistry. Silylation of the U VI oxo groups by bis(trimethylsilyl)pyrazine occurs first at only the unencapsulated exo oxo and only one silylation is needed to enable migration of the endo oxo out of the cone, whereupon a second silylation affords the stable U IV cis‐ bis(siloxide) [A] 2 [U(OSiMe 3 ) 2 (TC4A)]. Calculations confirm that only one silylation event is needed to initiate oxo rearrangement, and that the putative cis dioxo isomer of [UO 2 (TC4A)] 2− would be stable if it could be accessed synthetically, at only 23 kcal.mol −1 in energy above the classical trans dioxo. Calculations for the transuranic cis [AnO 2 (TC4A)] 2− (An=Np, Pu) are at higher energies, 30–35 kcal.mol −1 , retaining the U complexes as the more obvious target for a cis ‐dioxo actinyl ion. The aryloxide (OAr) groups of the macrocycle are essential in stabilizing this as‐yet unseen uranyl geometry as further bonding in the TC4A U‐O Ar groups stabilizes the U=O ‘yl’ bonds, explaining the stability of the putative cis [UO 2 (TC4A)] 2− in this ligand framework.
Understanding the chemistry of the inert actinide oxo bond in actinyl ions AnO2 2+ is important for controlling actinide behavior in the environment, during separations, and in nuclear waste (An=U, Np, Pu). The thioether calixarene TC4A (4-tert-butyltetrathiacalix[4]arene) binds equatorially to the actinyl cation forming a conical pocket that differentiates the two trans-oxo groups. The 'ate' complexes, [A]2[UO2(TC4A)] (A=[Li(DME)2], HNEt3) and [HNEt3]2[AnO2(TC4A)] (An=U, Np, Pu), enable selective oxo chemistry. Silylation of the UVI oxo groups by bis(trimethylsilyl)pyrazine occurs first at only the unencapsulated exo oxo and only one silylation is needed to enable migration of the endo oxo out of the cone, whereupon a second silylation affords the stable UIV cis-bis(siloxide) [A]2[U(OSiMe3)2(TC4A)]. Calculations confirm that only one silylation event is needed to initiate oxo rearrangement, and that the putative cis dioxo isomer of [UO2(TC4A)]2- would be stable if it could be accessed synthetically, at only 23 kcal.mol-1 in energy above the classical trans dioxo. Calculations for the transuranic cis[AnO2(TC4A)]2- (An=Np, Pu) are at higher energies, 30-35 kcal.mol-1, retaining the U complexes as the more obvious target for a cis-dioxo actinyl ion. The aryloxide (OAr) groups of the macrocycle are essential in stabilizing this as-yet unseen uranyl geometry as further bonding in the TC4A U-OAr groups stabilizes the U=O 'yl' bonds, explaining the stability of the putative cis[UO2(TC4A)]2- in this ligand framework.
Abstract Na n MAn 6 F 30 is an extremely versatile framework structure for incorporating tetravalent actinides (An) and cerium along with divalent or trivalent d‐metals (M); moreover, the structure exhibits a high resistance to harsh chemical conditions. This extreme robustness can potentially be exploited for the sequestration of plutonium in a stable matrix; however, no Na n MPu 6 F 30 compounds have been reported so far. Herein, we present four new plutonium fluorides that have been prepared as single crystals by mild hydrothermal synthesis methods. Structural characterizations revealed their compositions to be Na 3 AlPu 6 F 30 , Na 3 FePu 6 F 30 , Na 3 CoPu 6 F 30 , and Na 2.4 Mn 1.6 Pu 6 F 30 . Surprisingly, in the plutonium series, it was found that Co 2+ and Mn 2+ precursors oxidized to form Na 3 Co III Pu 6 F 30 and Na 2.4 Mn II/III 1.6 Pu 6 F 30 , whereas the analogous reactions for cerium result in reduction of the transition metal, even when beginning with a M 3+ precursor. While cerium is often used as a surrogate for plutonium, this work serves as an example that deviations between their chemistries do occur.
Abstract Polyurethane foam (PUF) can absorb sound by air friction and structural vibrations of cell walls. It is widely used as acoustic material in the automotive industry. According to existing studies, graphene oxide (GO) can improve the acoustic properties of PUF. However, GO tends to coalesce inside PUF. In this paper, straw fibers were modified with different concentrations of GO solution to embed GO on the surface of plant fibers. The GO was dispersed in the PUF using straw fibers. In addition, some studies show that the wrinkled morphology of the GO surface is believed to play a mechanical interlocking role in improving interfacial bonding, thus enhancing the stress transfer between the plant fibers and the polyurethane (PU) matrix and improving the mechanical properties of the PU composites. The acoustic and mechanical properties of the modified PU materials were observed by treating plant fibers with appropriate amounts of GO solution. The experimental study shows that the sample modified with 1 g L −1 GO solution reaches a maximum average sound absorption coefficient of 0.5838 when the straw fiber content reaches 0.5 g, and the sample modified with 2 g L −1 GO solution reaches a maximum transmission loss of 10.5333 when the straw fiber content reaches 1 g. © 2022 Society of Industrial Chemistry.
Here, two new approaches to measure Np concentration in dissolved used nuclear fuel simulant (aqueous feed for PUREX process) by spectrophotometry are developed. The first approach is based on chemical reduction of Np in the feed to its tetravalent state using ascorbic acid with simultaneous conversion of Pu(IV) to Pu(III). Interfering effects from light absorbing fission and corrosion products are accounted for by measuring optical absorbance spectrum of aqueous raffinate after extraction of U, Np, and Pu by tributyl phosphate in dodecane. The second approach uses no chemical treatment at all and relies on spontaneous valency adjustment of Np to Np(V) by dilution of the feed with water to reduce its acidity to low decimolar range of nitric acid concentration. Results of Np determination in the feed by spectrophotometry are in good agreement with its concentration measured by ICP-MS.
The use of element isotope ratios has great potential in not only determining the reactor type used to produce plutonium (Pu) but also in determining the burnup and the time since irradiation. While a powerful nuclear forensic technique, determining element isotope ratios is complicated by severe isobaric interferences when performed on typical inductively coupled plasma mass spectrometers. Such analyses require extensive chemical separations prior to analysis to alleviate the inter-elemental isobars. Ultrahigh mass resolution spectrometry provides a potential alternative, greatly reducing the complexity of sample preparation and turnaround times for these critical measurements. To demonstrate the power of the approach, a sample of irradiated, depleted uranium was analyzed with the liquid sampling—atmospheric pressure glow discharge ion source coupled to an Orbitrap mass spectrometer. The Orbitrap is augmented with an external data acquisition system, Spectroswiss’s FTMS-Booster X2T, allowing collection of extended ion transients, providing higher mass resolution. In using this approach, the 150 Sm/ 149 Sm and 152 Sm/ 149 Sm isotope ratios were found to be within 20% of predicted values without any chemical separations and without mass bias corrections. In addition, the 240 Pu/ 239 Pu isotope ratio was determined, free from the 238 UH + interferences common to the ICP-MS platforms, while at the same time allowing for the determination of U isotopic signatures. While these demonstrative results are from a single sample, the advantages of the microplasma/ultrahigh mass resolution approach to intra-element isotope ratio determinations are clear.