Synthesis of Ba(II) analogs of Ln(II)-in-(2.2.2-cryptand) and layered hexagonal net Ln(II) complexes, [(THF)Cs(µ–η5:η5–C5H4SiMe3)3LnII]

Huh, Daniel N.; Ciccone, Sierra R.; Moore, William N. G.; Evans, William J.

doi:10.1016/j.poly.2021.115493

Cited by 3 publications

(8 citation statements)

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“…A single 133 Cs resonance is observed for 2 at −218.62 ppm, and it is nearly identical with that of the previously characterized Yb(II) analogue (δ = −218.18 ppm). 25 This suggests that the cesium cations have similar chemical environments in solution. No signal was observed in the X-band CW EPR spectrum of 2 taken in perpendicular mode at 77 K, which is consistent with the strong spin−orbit coupling associated with the anisotropic 4f 13 electron configuration that induces relatively fast electron relaxation.…”

Section: ■ Introductionmentioning

confidence: 99%

“…Moreover, it is notable that the layered structure appears robust in the face of changing M(II) ions. 25 In fact, the THF solvation level can vary as well, tuning the planarity of the layered structure. 25 Substituting diamagnetic Yb(II) with a paramagnetic analogue was of interest because the hexagonal network incorporates these ions in a triangular orientation that offers the potential for spin frustration at low temperatures.…”

Section: ■ Introductionmentioning

confidence: 99%

“…25 In fact, the THF solvation level can vary as well, tuning the planarity of the layered structure. 25 Substituting diamagnetic Yb(II) with a paramagnetic analogue was of interest because the hexagonal network incorporates these ions in a triangular orientation that offers the potential for spin frustration at low temperatures. In order to explore the exfoliation of this type of structure with an S = 1/2 paramagnetic compound, rather than diamagnetic 1, the 4f 13 Tm(II) analogue [(THF)Cs(μ-η 5 :η 5 -Cp′) 3 Tm II ] n (2), was synthesized.…”

Section: ■ Introductionmentioning

confidence: 99%

“…Recently, an organometallic rare-earth compound, [(THF)Cs(μ-η 5 :η 5 -Cp′) 3 Yb II ] n ( 1 ; Cp′ = C 5 H 4 SiMe 3 ), was synthesized and found to have a layered structure (see Figure ) that could potentially be exfoliated to form thin films . Compound 1 is one of several recent structures that crystallize with layers of hexagonal networks comprised of three M(II) ions (M = Ba, Yb, and U) and three Cs(I) ions connected by bridging Cp′ ligands. , The trimethylsilyl groups of the Cp′ ligand and the methylene groups of the bound THF molecules extend outward perpendicular to the layer plane but do not form covalent bonds with other layers. The interlayer distance of approximately 1.8 Å between these functional groups is on the shorter side for a vdW material, but this crystal system seemed promising for exfoliation studies.…”

Section: Introductionmentioning

confidence: 99%

“…The interlayer distance of approximately 1.8 Å between these functional groups is on the shorter side for a vdW material, but this crystal system seemed promising for exfoliation studies. Moreover, it is notable that the layered structure appears robust in the face of changing M(II) ions . In fact, the THF solvation level can vary as well, tuning the planarity of the layered structure …”

Section: Introductionmentioning

confidence: 99%

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van der Waals Heterostructures Based on Nanolayered Paramagnetic Tm(II) Compounds and Boron Nitride for Investigating Spin Frustration

Moore

McSorley

Vincent

et al. 2023

ACS Appl. Nano Mater.

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The utility of molecular precursors to create thin-film components for constructing van der Waals heterostructures was explored by studying the layered Tm(II) compound [(THF)Cs(μ-η5:η5-Cp′)3TmII] n (Cp′ = C5H4SiMe3). This compound, synthesized by the reduction of Cp′3TmIII with metallic cesium, crystallizes as layers of hexagonal nets composed of Tm(II) ions and Cs(I) ions at alternating vertices, bridged by Cp′ ligands. Full characterization of the compound, including SQUID magnetometry, was consistent with 4f13 Tm(II). Though the triangular orientation of S = 1/2 Tm(II) ions in the layered structure indicated a potential environment for spin frustration, the SQUID data suggest these metal centers lack enough interaction to enforce such behavior. Successful exfoliation of the air- and moisture-sensitive single crystals was achieved in a glovebox at low temperatures to yield thin films. These could be stacked under hexagonal boron nitride to create an air-stable van der Waals heterostructure, which allowed analysis by AFM to determine a thickness of approximately 50 layers for the covered Tm-containing structure.

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Section: ■ Introductionmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

van der Waals Heterostructures Based on Nanolayered Paramagnetic Tm(II) Compounds and Boron Nitride for Investigating Spin Frustration

Moore

McSorley

Vincent

et al. 2023

ACS Appl. Nano Mater.

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Synthesis, Structures, and Equilibrium Reactions of La(III) and Ba(II) Complexes with Pyridine Phosphonate Pendant Arms on a Diaza-18-crown-6 Ether

Baba

Nagata

Yajima

et al. 2022

Bulletin of the Chemical Society of Japan

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Structures of La(III) and Ba(II) complexes and their stabilities were investigated to develop a stable chelating ligand for Ac(III) and Ra(II) which are of interest in nuclear medicine using alpha particles. The La(III) and Ba(II) complexes (1 and 2) with a diaza-18-crown-6 ether bearing pyridine phosphonic acid ethyl ester pendant arms (L1) and the complexes (3 and 4) with a diaza-18-crown-6 ether bearing pyridine phosphonate pendant arms ((H2L2)2−) were synthesized and characterized. The structures of the new complexes were determined by single-crystal X-ray analysis. The La(III) complexes, 1 and 3, exhibited 11-coordinate structures, whereas the Ba(II) complexes, 2 and 4 exhibited 11- and 10-coordinate geometries, respectively. Potentiometric titrations were performed to determine the acid–base equilibrium and the complex formation constants of the La(III) and Ba(II) complexes. In addition, the speciation analysis of the complexes was performed and the pH dependencies of the fractions in the aqueous solutions were investigated. For the La(III) complexes, the species with the ligand bearing pyridine phosphonate pendant arms were observed to be more stable than those with the ligand bearing pyridine phosphonate ester pendant arms. The Ba(II) complexes showed the opposite trend. The species with the pyridine phosphonate ester ligand were observed to be more stable than the species with the pyridine phosphonate type ligand.

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Thermally stable Terbium(II) and Dysprosium(II) Bis-Amidinate Single-Molecule Magnets

Jin

Luo

Gransbury

et al. 2023

Preprint

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The thermostable four-coordinate divalent lanthanide (Ln) bis-amidinate complexes [Ln(Piso)2] (Ln = Tb, Dy; Piso = {(NDipp)2CtBu}, Dipp = C6H3iPr2-2,6) were prepared by the reduction of parent five-coordinate Ln(III) precursors [Ln(Piso)2I] (Ln = Tb, Dy) with KC8; halide abstraction of [Ln(Piso)2I] with [H(SiEt3)2][B(C6F5)] gave the respective Ln(III) complexes [Ln(Piso)2][B(C6F5)]. All complexes were characterized by single crystal and powder XRD, SQUID magnetometry UV-vis-NIR, ATR-IR, NMR and EPR spectroscopy, and ab initio CASSCF-SO calculations. These data consistently show that [Ln(Piso)2] formally exhibit Ln(II) centers with 4fn5dz21 (Ln = Tb, n = 8; Dy, n = 9) valence electron configurations. We show that simple assignments of the f-d coupling to either L−S or J−s schemes is an oversimplification, especially in the presence of significant crystal field splitting. The coordination geometry of [Ln(Piso)2] is intermediate between square planar and tetrahedral. Projecting from the quaternary carbon atoms of the CN2 ligand backbones shows near-linear C···Ln···C arrangements. This results in strong axial ligand fields to give effective energy barriers to magnetic relaxation of 1920(91) K for the Tb(II) analog and 1964(48) K for Dy(II), the highest values observed to date for any mononuclear Ln(II) single-molecule magnet (SMM).

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Synthesis of Ba(II) analogs of Ln(II)-in-(2.2.2-cryptand) and layered hexagonal net Ln(II) complexes, [(THF)Cs(µ–η5:η5–C5H4SiMe3)3LnII]

Cited by 3 publications

References 30 publications

van der Waals Heterostructures Based on Nanolayered Paramagnetic Tm(II) Compounds and Boron Nitride for Investigating Spin Frustration

van der Waals Heterostructures Based on Nanolayered Paramagnetic Tm(II) Compounds and Boron Nitride for Investigating Spin Frustration

Synthesis, Structures, and Equilibrium Reactions of La(III) and Ba(II) Complexes with Pyridine Phosphonate Pendant Arms on a Diaza-18-crown-6 Ether

Thermally stable Terbium(II) and Dysprosium(II) Bis-Amidinate Single-Molecule Magnets

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