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At least 505 records · Page 28
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on EuMg2 by Materials Project

EuMg2 is Cubic Laves structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are two inequivalent Mg sites. In the first Mg site, Mg is bonded to six equivalent Mg and six equivalent Eu atoms to form a mixture of edge, corner, and face-sharing MgEu6Mg6 cuboctahedra. All Mg–Mg bond lengths are 3.14 Å. All Mg–Eu bond lengths are 3.68 Å. In the second Mg site, Mg is bonded to six Mg and six equivalent Eu atoms to form a mixture of edge, corner, and face-sharing MgEu6Mg6 cuboctahedra. All Mg–Mg bond lengths are 3.14 Å. All Mg–Eu bond lengths are 3.68 Å. Eu is bonded in a 12-coordinate geometry to twelve Mg and four equivalent Eu atoms. There are three shorter (3.84 Å) and one longer (3.85 Å) Eu–Eu bond lengths.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CaEuSi4 by Materials Project

CaEuSi4 is hexagonal omega structure-derived structured and crystallizes in the tetragonal I-4m2 space group. The structure is three-dimensional. Ca is bonded to twelve Si atoms to form CaSi12 cuboctahedra that share edges with four equivalent CaSi12 cuboctahedra, edges with eight equivalent EuSi12 cuboctahedra, faces with four equivalent CaSi12 cuboctahedra, and faces with four equivalent EuSi12 cuboctahedra. There are four shorter (3.10 Å) and eight longer (3.23 Å) Ca–Si bond lengths. Eu is bonded to twelve Si atoms to form EuSi12 cuboctahedra that share edges with four equivalent EuSi12 cuboctahedra, edges with eight equivalent CaSi12 cuboctahedra, faces with four equivalent CaSi12 cuboctahedra, and faces with four equivalent EuSi12 cuboctahedra. There are four shorter (3.10 Å) and eight longer (3.23 Å) Eu–Si bond lengths. There are five inequivalent Si sites. In the first Si site, Si is bonded in a 9-coordinate geometry to four equivalent Ca, two equivalent Eu, and three Si atoms. There are one shorter (2.30 Å) and two longer (2.40 Å) Si–Si bond lengths. In the second Si site, Si is bonded in a 9-coordinate geometry to two equivalent Ca, four equivalent Eu, and three Si atoms. The Si–Si bond length is 2.29 Å. In the third Si site, Si is bonded in a 9-coordinate geometry to two equivalent Ca, four equivalent Eu, and three Si atoms. There are one shorter (2.29 Å) and two longer (2.40 Å) Si–Si bond lengths. In the fourth Si site, Si is bonded in a 9-coordinate geometry to four equivalent Ca, two equivalent Eu, and three Si atoms. All Si–Ca bond lengths are 3.23 Å. Both Si–Eu bond lengths are 3.10 Å. There are one shorter (2.30 Å) and two longer (2.40 Å) Si–Si bond lengths. In the fifth Si site, Si is bonded in a 9-coordinate geometry to four equivalent Ca, two equivalent Eu, and three Si atoms. All Si–Ca bond lengths are 3.23 Å. Both Si–Si bond lengths are 2.40 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Eu5Bi3 by Materials Project

Eu5Bi3 crystallizes in the hexagonal P6_3/mcm space group. The structure is three-dimensional. there are two inequivalent Eu sites. In the first Eu site, Eu is bonded in a 6-coordinate geometry to six equivalent Bi atoms. All Eu–Bi bond lengths are 3.48 Å. In the second Eu site, Eu is bonded in a 5-coordinate geometry to five equivalent Bi atoms. There are a spread of Eu–Bi bond distances ranging from 3.30–3.86 Å. Bi is bonded in a 9-coordinate geometry to nine Eu atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Eu5Sb3 by Materials Project

Eu5Sb3 crystallizes in the hexagonal P6_3/mcm space group. The structure is three-dimensional. there are two inequivalent Eu sites. In the first Eu site, Eu is bonded in a 6-coordinate geometry to six equivalent Sb atoms. All Eu–Sb bond lengths are 3.39 Å. In the second Eu site, Eu is bonded in a 5-coordinate geometry to five equivalent Sb atoms. There are a spread of Eu–Sb bond distances ranging from 3.21–3.76 Å. Sb is bonded in a 9-coordinate geometry to nine Eu atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Eu3Au by Materials Project

Eu3Au is Cementite structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Eu sites. In the first Eu site, Eu is bonded in a 2-coordinate geometry to three equivalent Au atoms. There are a spread of Eu–Au bond distances ranging from 3.15–3.57 Å. In the second Eu site, Eu is bonded in a bent 150 degrees geometry to two equivalent Au atoms. There are one shorter (3.10 Å) and one longer (3.14 Å) Eu–Au bond lengths. Au is bonded in a 8-coordinate geometry to eight Eu atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Eu2Sn by Materials Project

Eu2Sn is Cotunnite structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Eu sites. In the first Eu site, Eu is bonded to five equivalent Sn atoms to form a mixture of distorted corner and edge-sharing EuSn5 tetrahedra. There are a spread of Eu–Sn bond distances ranging from 3.29–4.03 Å. In the second Eu site, Eu is bonded in a 5-coordinate geometry to five equivalent Sn atoms. There are a spread of Eu–Sn bond distances ranging from 3.44–3.80 Å. Sn is bonded in a 10-coordinate geometry to ten Eu atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Eu2Ge by Materials Project

Eu2Ge is Cotunnite structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Eu sites. In the first Eu site, Eu is bonded in a 5-coordinate geometry to five equivalent Ge atoms. There are a spread of Eu–Ge bond distances ranging from 3.16–3.69 Å. In the second Eu site, Eu is bonded to four equivalent Ge atoms to form a mixture of edge and corner-sharing EuGe4 tetrahedra. There are a spread of Eu–Ge bond distances ranging from 3.07–3.14 Å. Ge is bonded in a 9-coordinate geometry to nine Eu atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Eu2In by Materials Project

Eu2In is Cotunnite structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Eu sites. In the first Eu site, Eu is bonded in a 5-coordinate geometry to five equivalent In atoms. There are three shorter (3.45 Å) and two longer (3.82 Å) Eu–In bond lengths. In the second Eu site, Eu is bonded in a 4-coordinate geometry to five equivalent In atoms. There are a spread of Eu–In bond distances ranging from 3.32–4.00 Å. In is bonded in a 10-coordinate geometry to ten Eu atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on EuAl8SiAu4 by Materials Project

EuAu4Al8Si crystallizes in the tetragonal P4mm space group. The structure is three-dimensional. Eu is bonded in a 8-coordinate geometry to four equivalent Au, eight Al, and four equivalent Si atoms. All Eu–Au bond lengths are 3.33 Å. There are four shorter (3.42 Å) and four longer (3.52 Å) Eu–Al bond lengths. All Eu–Si bond lengths are 3.23 Å. There are four inequivalent Au sites. In the first Au site, Au is bonded in a body-centered cubic geometry to eight Al atoms. All Au–Al bond lengths are 2.62 Å. In the second Au site, Au is bonded in a body-centered cubic geometry to eight Al atoms. There are four shorter (2.61 Å) and four longer (2.65 Å) Au–Al bond lengths. In the third Au site, Au is bonded in a body-centered cubic geometry to eight Al atoms. There are four shorter (2.59 Å) and four longer (2.64 Å) Au–Al bond lengths. In the fourth Au site, Au is bonded in a 9-coordinate geometry to four equivalent Eu, four equivalent Al, and one Si atom. All Au–Al bond lengths are 2.58 Å. The Au–Si bond length is 2.47 Å. There are four inequivalent Al sites. In the first Al site, Al is bonded to two equivalent Eu and four Au atoms to form a mixture of face, edge, and corner-sharing AlEu2Au4 tetrahedra. In the second Al site, Al is bonded to two equivalent Eu, two equivalent Au, and two equivalent Si atoms to form distorted AlEu2Si2Au2 tetrahedra that share corners with fourteen AlEu2Au4 tetrahedra, edges with four AlEu2Au4 tetrahedra, and faces with four equivalent AlEu2Si2Au2 tetrahedra. Both Al–Si bond lengths are 2.65 Å. In the third Al site, Al is bonded to four Au atoms to form a mixture of edge and corner-sharing AlAu4 tetrahedra. In the fourth Al site, Al is bonded to four Au atoms to form a mixture of edge and corner-sharing AlAu4 tetrahedra. Si is bonded in a 1-coordinate geometry to four equivalent Eu, one Au, and four equivalent Al atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Understanding the Stabilization and Tunability of Divalent Europium 2.2.2B Cryptates

Lanthanides such as europium with more accessible divalent states are useful for studying redox stability afforded by macrocyclic organic ligands. Substituted cryptands, such as 2.2.2B cryptand, that increase the oxidative stability of divalent europium also provide coordination environments that support synthetic alterations of Eu(II) cryptate complexes. Two single crystal structures were obtained containing nine-coordinate Eu(II) 2.2.2B cryptate complexes that differ by a single coordination site, the occupation of which is dictated by changes in reaction conditions. A crystal structure containing a [Eu(2.2.2B)Cl] + complex is obtained from a methanol–THF solvent mixture, while a methanol–acetonitrile solvent mixture affords a [Eu(2.2.2B)(CH 3 OH)] 2+ complex. While both crystals exhibit the typical blue emission observed in most Eu(II) containing compounds as a result of 4f 6 5d 1 to 4f 7 transitions, computational results show that the substitution of a Cl– anion in the place of a methanol molecule causes mixing of the 5d excited states in the Eu(II) 2.2.2B cryptate complex. Additionally, magnetism studies reveal the identity of the capping ligand in the Eu(II) 2.2.2B cryptate complex may also lead to exchange between Eu(II) metal centers facilitated by π-stacking interactions within the structure, slightly altering the anticipated magnetic moment. Finally, the synthetic control present in these systems makes them interesting candidates for studying less stable divalent lanthanides and the effects of precise modifications of the electronic structures of low valent lanthanide elements.

Anions↗
DOE OSTI2024

Determining the Effects of Zero-Field Splitting and Magnetic Exchange in Dimeric Europium(II) Complexes

Related BAP [BAP = bis(acyl)phosphide] and Acac (Acac = β-diketonate) molecules perform as robust supports for both lanthanide and actinide metals. Here, a molecular bimetallic Eu 2+ complex was successfully targeted and isolated by employing sodium bis(mesitoyl)phosphide [Na( mes BAP)] in a salt metathesis with EuI 2 , producing [Eu( mes BAP) 2 (et 2 o)] 2 (et 2 o = metal-coordinated diethyl ether). The corresponding Acac-Eu 2+ complex was targeted using mes Acac– (1,3-dimesityl-1,3-propanedione), generating [Eu( mes Acac) 2 (et 2 o)] 2 . Both complexes were characterized by single-crystal X-ray diffraction, UV–vis, IR, and NMR spectroscopies, and variable-temperature magnetic susceptibility. [Eu( mes BAP) 2 (et 2 o)] 2 was persistent under anaerobic, anhydrous conditions, whereas the analogous [Eu( mes Acac) 2 (et 2 o)] 2 showed evidence of decomposition under identical conditions. Finally, variable-temperature magnetic susceptibility and magnetization studies of [Eu( mes BAP) 2 (et 2 o)] 2 and [Eu( mes Acac) 2 (et 2 o)] 2 were performed, resulting in similar magnetic exchange coupling values of J ex = –0.018 and –0.023 cm –1 and axial zero-field-splitting D values of –0.38 and –0.51 cm –1 , respectively.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Multiscale investigations of europium(III) complexation with tetra- n -octyl diglycolamide confined in porous solid supports

The microscopic, short-range coordination environments and mesoscopic, long-range structures of Eu 3+ contacted with tetra-n-octyl diglycolamide (TODGA) confined on ordered mesoporous carbon (OMC) nanoparticles and Amberchrom CG 71 resin were probed using Eu L 3 -edge extended X ray absorption fine structure (EXAFS) as well as small-angle and wide-angle X ray scattering, SAXS and WAXS, respectively. A homoleptic Eu(TODGA) 3 3+ coordination complex typical of liquid-liquid extraction (LLE) chemistry is present under low Eu 3+ loading conditions on both solid supports. Deviations from this traditional structure motif appear at hyperstoichiometric Eu 3+ loadings, above the 1:3 Eu 3+ to TODGA mole ratio. Microcrystalline-like domains with multinuclear Eu speciation are templated by use of these high Eu 3+ loading conditions with the functionalized OMC materials, highlighting a major departure of liquid-solid extraction chromatography (EXC) from the coordination chemistry of LLE. No such long-range spatial coherence was observed for analogous polyacrylic resin materials. Furthermore, these results demonstrate both the similarities and differences between multiscale structures in LLE and EXC, underscoring the opportunities for improved separation techniques based on solid supports with long-range spatial coherence (e.g., OMC systems) and without it (e.g., resin materials). Since crystallization was the first approach to adjacent lanthanide separations, the prospect of templating microcrystalline TODGA-lanthanide complexes that are otherwise not prone to crystallization by use of OMC nanoparticles represents a new entry to addressing long-standing issues in purification by liquid-solid phase separation.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Materials Data on EuIn4Pd by Materials Project

EuPdIn4 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Eu is bonded in a 5-coordinate geometry to two equivalent Pd and thirteen In atoms. Both Eu–Pd bond lengths are 3.50 Å. There are a spread of Eu–In bond distances ranging from 3.29–3.86 Å. Pd is bonded in a 9-coordinate geometry to two equivalent Eu and seven In atoms. There are a spread of Pd–In bond distances ranging from 2.70–2.84 Å. There are three inequivalent In sites. In the first In site, In is bonded in a distorted q6 geometry to four equivalent Eu and six In atoms. There are four shorter (3.19 Å) and two longer (3.20 Å) In–In bond lengths. In the second In site, In is bonded in a 3-coordinate geometry to three equivalent Eu, three equivalent Pd, and one In atom. In the third In site, In is bonded in a 2-coordinate geometry to three equivalent Eu, one Pd, and four equivalent In atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Eu2B4Rh5 by Materials Project

Eu2Rh5B4 crystallizes in the orthorhombic Fmmm space group. The structure is three-dimensional. Eu is bonded in a 8-coordinate geometry to ten Rh and six equivalent B atoms. There are a spread of Eu–Rh bond distances ranging from 3.10–3.29 Å. There are two shorter (3.04 Å) and four longer (3.21 Å) Eu–B bond lengths. There are three inequivalent Rh sites. In the first Rh site, Rh is bonded in a distorted square co-planar geometry to four equivalent Eu and four equivalent B atoms. All Rh–B bond lengths are 2.20 Å. In the second Rh site, Rh is bonded in a 4-coordinate geometry to four equivalent Eu and four equivalent B atoms. All Rh–B bond lengths are 2.13 Å. In the third Rh site, Rh is bonded in a distorted square co-planar geometry to four equivalent Eu and four equivalent B atoms. All Rh–B bond lengths are 2.18 Å. B is bonded in a 5-coordinate geometry to three equivalent Eu and five Rh atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on EuIn2(GeIr)4 by Materials Project

EuIn2(IrGe)4 crystallizes in the tetragonal I-42m space group. The structure is three-dimensional. Eu is bonded in a 12-coordinate geometry to four equivalent Ir, four equivalent In, and eight equivalent Ge atoms. All Eu–Ir bond lengths are 3.51 Å. All Eu–In bond lengths are 3.51 Å. There are four shorter (3.25 Å) and four longer (3.58 Å) Eu–Ge bond lengths. Ir is bonded in a 6-coordinate geometry to one Eu, two equivalent In, and four equivalent Ge atoms. Both Ir–In bond lengths are 2.79 Å. There are a spread of Ir–Ge bond distances ranging from 2.40–2.63 Å. In is bonded in a 10-coordinate geometry to two equivalent Eu, four equivalent Ir, and four equivalent Ge atoms. All In–Ge bond lengths are 3.09 Å. Ge is bonded in a 5-coordinate geometry to two equivalent Eu, four equivalent Ir, and two equivalent In atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on EuIn4Cu by Materials Project

EuCuIn4 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Eu is bonded in a 1-coordinate geometry to two equivalent Cu and thirteen In atoms. Both Eu–Cu bond lengths are 3.42 Å. There are a spread of Eu–In bond distances ranging from 3.30–3.80 Å. Cu is bonded in a 9-coordinate geometry to two equivalent Eu and seven In atoms. There are a spread of Cu–In bond distances ranging from 2.65–2.84 Å. There are three inequivalent In sites. In the first In site, In is bonded in a distorted q6 geometry to four equivalent Eu and six In atoms. There are two shorter (3.18 Å) and four longer (3.20 Å) In–In bond lengths. In the second In site, In is bonded in a 2-coordinate geometry to three equivalent Eu, one Cu, and eight In atoms. All In–In bond lengths are 3.34 Å. In the third In site, In is bonded in a 12-coordinate geometry to three equivalent Eu, three equivalent Cu, and six In atoms. There are one shorter (2.97 Å) and two longer (3.27 Å) In–In bond lengths.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on EuIn4Au by Materials Project

EuAuIn4 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Eu is bonded in a 1-coordinate geometry to two equivalent Au and thirteen In atoms. Both Eu–Au bond lengths are 3.49 Å. There are a spread of Eu–In bond distances ranging from 3.26–3.93 Å. Au is bonded in a 9-coordinate geometry to two equivalent Eu and seven In atoms. There are a spread of Au–In bond distances ranging from 2.79–2.93 Å. There are three inequivalent In sites. In the first In site, In is bonded in a 3-coordinate geometry to three equivalent Eu, three equivalent Au, and one In atom. The In–In bond length is 3.10 Å. In the second In site, In is bonded in a 2-coordinate geometry to three equivalent Eu, one Au, and four equivalent In atoms. All In–In bond lengths are 3.22 Å. In the third In site, In is bonded in a distorted q6 geometry to four equivalent Eu and six In atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on EuIn4Ir by Materials Project

EuIrIn4 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Eu is bonded in a 5-coordinate geometry to two equivalent Ir and thirteen In atoms. Both Eu–Ir bond lengths are 3.47 Å. There are a spread of Eu–In bond distances ranging from 3.33–3.84 Å. Ir is bonded in a 7-coordinate geometry to two equivalent Eu and seven In atoms. There are a spread of Ir–In bond distances ranging from 2.69–2.82 Å. There are three inequivalent In sites. In the first In site, In is bonded in a 3-coordinate geometry to three equivalent Eu, three equivalent Ir, and one In atom. The In–In bond length is 3.20 Å. In the second In site, In is bonded in a 1-coordinate geometry to three equivalent Eu, one Ir, and four equivalent In atoms. All In–In bond lengths are 3.16 Å. In the third In site, In is bonded in a distorted q6 geometry to four equivalent Eu and six In atoms.

36 MATERIALS SCIENCE↗