Results for “Eu(NO3)3” | Engineering Papers

DOE OSTI2020

Materials Data on Eu(NO3)3 by Materials Project

Eu(NO3)3 crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of one Eu(NO3)3 sheet oriented in the (0, 0, 1) direction. Eu3+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Eu–O bond distances ranging from 2.46–2.67 Å. There are three inequivalent N5+ sites. In the first N5+ site, N5+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of N–O bond distances ranging from 1.25–1.28 Å. In the second N5+ site, N5+ is bonded in a trigonal planar geometry to three O2- atoms. There is two shorter (1.26 Å) and one longer (1.27 Å) N–O bond length. In the third N5+ site, N5+ is bonded in a trigonal planar geometry to three O2- atoms. There is two shorter (1.25 Å) and one longer (1.30 Å) N–O bond length. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Eu3+ and one N5+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to one Eu3+ and one N5+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Eu3+ and one N5+ atom. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to one Eu3+ and one N5+ atom. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to one Eu3+ and one N5+ atom. In the sixth O2- site, O2- is bonded in a distorted single-bond geometry to one Eu3+ and one N5+ atom. In the seventh O2- site, O2- is bonded in a distorted single-bond geometry to one Eu3+ and one N5+ atom. In the eighth O2- site, O2- is bonded in a distorted single-bond geometry to one Eu3+ and one N5+ atom. In the ninth O2- site, O2- is bonded in a distorted single-bond geometry to one Eu3+ and one N5+ atom.

36 MATERIALS SCIENCE↗

DOE OSTI2021

Gas-Phase Stability of Large Lanthanide:Ligand Clusters Evaluated Using Collision-Induced Dissociation

Introduction In the reprocessing of f-elements present in used nuclear fuels, a variety of diglycolamides (DGA’s) are used as extractants for actinide partitioning. In particular, the Actinide-Lanthanide Separation (ALSEP) process typically utilizes either the N,N,N’,N’-tetraoctyl diglycolamide (TODGA) or N,N,N',N'-tetra-2-ethylhexyl diglycolamide (T2EHDGA) extractant ligands following the partitioning of uranium and plutonium from used nuclear fuel. To better understand fundamental interactions in these processes, covalent bonding of several f-elements with diglycolamides, primarily TODGA, is investigated in the gas phase using nanospray ionization and a quadrupole time-of-flight mass spectrometer. Further, analysis of the identity and relative strength of the cluster is enabled by MS2 isolation and collision induced dissociation. Methods Metal ion cluster analysis was completed using a Bruker (Billerica, MA, USA) mircOTOF-Q II quadrupole time-of-flight mass spectrometer with a CaptiveSpray nanospray ion source. Detection was accomplished using positive ionization mode. Metal: ligand solutions were assembled as 30 µM europium nitrate, samarium nitrate, cerium nitrate, or holmium nitrate and 3 µM DGA in acetonitrile or a 50:50 mixture of acetonitrile: isopropanol. Preliminary data The samarium cluster experiments yielded clusters with a samarium:TODGA ratio of up to 1:7 able to be isolated and evidence of greater ratios present in the mass spectrum. This is surprising, as metal clusters are not expected to have a coordination space able to accommodate this many TODGA ligands, due to its size and tridenticity. Collisional activation of [Sm(TODGA)3]3+ suggested loss of a TODGA radical cation, in addition to ligand fragmentation. In contrast, activation of clusters with higher Sm:TODGA ratios resulted in loss of entire ligands, with no evidence of fragmentation. A lower collision energy was required to remove ligands as the number of bound TODGAs increased, suggesting that in larger clusters, ligands are more delicately complexed to the metal. In addition, several clusters were observed with the composition [Sm(NO3)x(TODGA)n x]+3 x. With a single nitrate ion, clusters with up to six TODGAs were able to be isolated. In a similar pattern to the samarium clusters containing only TODGA, less collision energy was required to eliminate one or more TODGAs with increasing size. Clusters with composition [Sm(NO3)(TODGA)n-1]2+ appeared in lower abundance and were more collisionally stable than [Sm(TODGA)n]3+ clusters. With two nitrate ions, only clusters with a single TODGA were able to be isolated. Analogous europium experiments resulted in similar clusters. Ratios of up to 1:7 Eu:TODGA and clusters with one nitrate and up to five TODGAs were isolated. In clusters with two nitrate ions, only one or two TODGAs were observed to be bound. Similar to samarium, MS2 experiments with the Eu clusters suggested that larger clusters required less collision energy to eliminate TODGA. Europium clusters with the composition [Eu(NO3)(TODGA)n-1]2+ were observed in greater abundance and with greater stability than the equivalent cluster with the composition [Eu(TODGA)n]3+. Novel Aspect These are the first reported Ln:TODGA clusters, allowing us to begin to investigate intrinsic complexation of lanthanides with process-relevant ligands.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗