Results from a solid-state 139La NMR spectroscopic investigation of the anhydrous lanthanum(III) halides (LaX3; X=F, Cl, Br, I) at applied magnetic fields of 7.0, 9.4, 11.7, 14.1, and 17.6 T are presented and highlight the advantages of working at high applied magnetic field strengths. The 139La quadrupolar coupling constants are found to range from 15.55 to 24.0 MHz for LaCl3 and LaI3, respectively. The lanthanum isotropic chemical shifts exhibit an inverse halogen dependence with values ranging from -135 ppm for LaF3 to 700 ppm for LaI3, which represents nearly half of the total lanthanum chemical shift range. The spans of the magnetic shielding tensors also vary widely, from 35 to 650 ppm for the solid LaF3 through LaI3. DFT calculations of the 139La electric field gradient and magnetic shielding tensors have been performed and provide a qualitative interpretation of the trends observed experimentally.
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http://dx.doi.org/10.1016/j.ssnmr.2005.07.002 | DOI Listing |
Molecules
November 2024
Department of Chemistry, University of Munich (LMU), Butenandtstr. 5-13, 81377 Munich, Germany.
Based on their various and outstanding properties, binary nitrides are used as (synthesis) materials in industry and research. Hence, their comprehensive characterization by analytical methods is of particular interest. Since Nuclear Magnetic Resonance (NMR) spectroscopy is very sensitive to the symmetry of the electronic density distribution, it is a suitable tool for the investigation of rock-salt structure types and, especially, for those with known stoichiometry issues.
View Article and Find Full Text PDFJ Am Chem Soc
August 2024
Chemical and Biological Sciences Division, Ames National Laboratory, Ames, Iowa 50011, United States.
Materials with well-defined surfaces are drawing increased attention for the design of bespoke catalysts and nanomaterials. Gaining a detailed understanding of the surfaces of these materials is an important challenge, which is often complicated by surface polymorphism and dynamic restructuring. We introduce the use of surface-enhanced NMR spectroscopy for the observation of such surfaces, focusing on LaScO as an example.
View Article and Find Full Text PDFChemphyschem
April 2024
Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK.
Multinuclear Nuclear Magnetic Resonance (NMR) spectroscopy of quadrupolar nuclei at ultrahigh magnetic field provides compelling insight into the short-range structure in a family of fast oxide ion electrolytes with LaSrGaO melilite structure. The striking resolution enhancement in the solid-state Ga NMR spectra measured with the world's unique series connected hybrid magnet operating at 35.2 T distinctly resolves Ga sites in four- and five-fold coordination environments.
View Article and Find Full Text PDFInorg Chem
August 2022
Univ Rennes, INSA Rennes, ENSCR, CNRS UMR 6226 "Institut des Sciences Chimiques de Rennes", 35708 Rennes, France.
Reactions in water at ambient temperature and pressure between a lanthanide ion and benzene-1,3,5-tricarboxylate (or trimesate) lead to two series of iso-structural coordination polymers. Their general chemical formula is [Ln(tma)(HO)] for the lightest lanthanide ions (Ln = La-Dy except ), while it is [Ln(tma)(HO)·3.5HO] for the heaviest ones (Ho-Lu plus Y).
View Article and Find Full Text PDFDalton Trans
September 2021
Department of Chemistry and Materials Sciences Center, Philipps-Universität Marburg, Hans Meerwein Straße 4, 35043 Marburg, Germany.
We report a new high-yield synthesis of so far not accessible tetraphenylphosphonium methylcarbonate PhP[OCOMe] solvothermal fluoride-induced demethylation and MeF elimination at MeCO (DMC) by PhP-F, structurally characterized as λ-fluorophosphoran by XRD. The synthetic value of PhP[OCOMe] key compound for preparing nearly all kinds of other PhP[anion] salts with perfectly crystallizing (not symmetry frustrated) cation is demonstrated by examples beyond ionic liquid research: a complete set of silylchalcogenide salts PhP[ESiMe] (E = S, Se, and Te) including the first example of a structurally characterized non-coordinating, naked [Te-SiMe] anion is presented. With this set of soft Lewis bases and metal organic Lewis acids [CpLa] at hand, a comprehensive series of crystalline 1 : 1 lanthanate complexes PhP[CpLa-ESiMe] has been prepared.
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