7Li solid-state NMR of lithium amides: structural information from7Li quadrupolar coupling constants

1998 ◽  
Vol 36 (S1) ◽  
pp. S61-S70 ◽  
Author(s):  
Michael Hartung ◽  
Harald Günther ◽  
Jean-Paul Amoureux ◽  
Christian Fernandéz
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Structural Information ◽  
Coupling Constants ◽  
Lithium Amides ◽  
Quadrupolar Coupling

Structural analysis of lanthanum-containing battery materials using 139La solid-state NMR

2011 ◽  
Vol 89 (9) ◽  
pp. 1105-1117 ◽  
Author(s):  
Leigh Spencer ◽  
Eric Coomes ◽  
Eric Ye ◽  
Victor Terskikh ◽  
Adam Ramzy ◽  
...  
Keyword(s):  
Solid State ◽  
Structural Analysis ◽  
Lithium Ion Battery ◽  
Solid State Nmr ◽  
Nmr Spectra ◽  
Lithium Ion ◽  
Atomic Level ◽  
Coupling Constants ◽  
Battery Materials ◽  
Quadrupolar Coupling

139La solid-state NMR spectra, acquired at 21.1 and 11.7 T, have been used to evaluate the structural properties of the lithium ion battery materials, La32Li16Fe6.4O67 and Li3xLa2/3–xTiO3. In particular, atomic-level disorder in the second coordination sphere environment of lanthanum in these materials has been indicated by the observation of a distribution in the asymmetry parameters and the quadrupolar coupling constants derived from experimental NMR spectra, and supported by theoretical calculations. For comparison, 139La NMR has been obtained for the two model compounds La2O3 and LaNbO4, in which there is no atomic-level disorder. Quadrupolar coupling constants in the range of 17 to 59 MHz have been measured, and these values are supported by previous work as well as theoretical predictions performed in CASTEP. It has been shown that 139La NMR is a useful tool for the structural analysis of lithium ion battery materials, and when combined with 7Li MAS NMR and powder X-ray diffraction, can be used to determine the structure of complex solid-state electrolyte and electrode materials.

A solid state NMR and molecular orbital study of hydroxylammonium chloride

1999 ◽  
Vol 77 (11) ◽  
pp. 1813-1820 ◽  
Author(s):  
Glenn H Penner ◽  
YC Phillis Chang ◽  
H Michelle Grandin
Keyword(s):  
Activation Energy ◽  
Solid State ◽  
Chemical Shift ◽  
Molecular Orbital ◽  
Solid State Nmr ◽  
Coupling Constants ◽  
Basis Sets ◽  
Exponential Factor ◽  
Line Shapes ◽  
Quadrupolar Coupling

Deuterium and nitrogen-15 NMR spectroscopy has been used to measure the 2H quadrupolar coupling and 15N chemical shift tensors in solid hydroxylammonium chloride, NH3OH+Cl-, (HAC). In addition, the NH3 and OH dynamics have been investigated by variable temperature 2H line shapes and T1 measurements. The Arrhenius activation energy for NH3 rotation is 22.5 ± 1.8 kJ/mol with a pre-exponential factor of 8 ± 3 × 1012 s-1 from line shapes and 21.3 ± 2 kJ/mol with an infinite temperature correlation time, τinf,, of 5.0 ± 0.4 × 10-14 s from the T1 analysis. The latter value corresponds to a pre-exponential factor of 6.7 ± 0.5 × 1012 s-1, if a three-site exchange is assumed. There was no evidence for OH reorientation up to 405 K, indicating a rather strong OH···Cl hydrogen bond. Previously reported inconsistencies between crystal structure and molecular orbital derived N-O bond lengths are cleared up by performing geometry optimizations with large basis sets and taking electron correlation into account. The internal rotational potential for the isolated HA cation is calculated to be 5.8 kJ/mol at the MP2/6-31G** level, with the trans geometry preferred. Calculations that employ the neutron diffraction geometry and include the Cl- anions that surround the HA+ cation yield an upper limit for the activation energy for NH3 group rotation of 62 kJ/mol. Analysis of the deuterium spectrum and T1 data yield nuclear quadrupolar coupling constants of 160 ± 5 kHz and 194 ± 5 kHz (η = 0.50 ± 0.05) for the ND3 and OD deuterons, respectively. Density functional calculations of the deuterium and nitrogen-14 nuclear quadrupolar coupling constants at the B3LYP level show that it is necessary to include the influence of the surrounding chloride anions. We have also shown that it is possible to obtain accurate proton chemical shifts from the deuterium MAS spectrum of solid HAC-d4.Key words: solid state NMR, molecular dynamics, nitrogen 15 chemical shift anisotropy.

Protein structure by solid-state NMR spectroscopy

1987 ◽  
Vol 19 (1-2) ◽  
pp. 7-49 ◽  
Author(s):  
S. J. Opella ◽  
P. L. Stewart ◽  
K. G. Valentine
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Solid State Nmr ◽  
Structural Information ◽  
Biological Systems ◽  
Genetic Regulation ◽  
Protein Structures ◽  
Crystalline Solid ◽  
Solid State Nmr Spectroscopy ◽  
Nmr Methods

The three-dimensional structures of proteins are among the most valuable contributions of biophysics to the understanding of biological systems (Dickerson & Geis, 1969; Creighton, 1983). Protein structures are utilized in the description and interpretation of a wide variety of biological phenomena, including genetic regulation, enzyme mechanisms, antibody recognition, cellular energetics, and macroscopic mechanical and structural properties of molecular assemblies. Virtually all of the information currently available about the structures of proteins at atomic resolution has been obtained from diffraction studies of single crystals of proteins (Wyckoff et al, 1985). However, recently developed NMR methods are capable of determining the structures of proteins and are now being applied to a variety of systems, including proteins in solution and other non-crystalline environments that are not amenable for X-ray diffraction studies. Solid-state NMR methods are useful for proteins that undergo limited overall reorientation by virtue of their being in the crystalline solid state or integral parts of supramolecular structures that do not reorient rapidly in solution. For reviews of applications of solid-state NMR spectroscopy to biological systems see Torchia and VanderHart (1979), Griffin (1981), Oldfield et al. (1982), Opella (1982), Torchia (1982), Gauesh (1984), Torchia (1984) and Opella (1986). This review describes how solid-state NMR can be used to obtain structural information about proteins. Methods applicable to samples with macroscopic orientation are emphasized.

scholarly journals Higher Magnetic Fields, Finer MOF Structural Information: 17O Solid-State NMR at 35.2 T

2020 ◽  
Vol 142 (35) ◽  
pp. 14877-14889 ◽  
Author(s):  
Vinicius Martins ◽  
Jun Xu ◽  
Xiaoling Wang ◽  
Kuizhi Chen ◽  
Ivan Hung ◽  
...  
Keyword(s):  
Solid State ◽  
Magnetic Fields ◽  
Solid State Nmr ◽  
Structural Information

A solid-state NMR investigation of the colossal expansion material, Ag3Co(CN)6

2012 ◽  
Vol 90 (10) ◽  
pp. 891-901 ◽  
Author(s):  
Brett C. Feland ◽  
Guy M. Bernard ◽  
Roderick E. Wasylishen
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Negative Thermal Expansion ◽  
Coupling Constant ◽  
Quadrupolar Coupling Constant ◽  
Quadrupolar Coupling ◽  
Field Gradients ◽  
Increasing Temperature ◽  
Nmr Properties ◽  
Expansion Behaviour

Presented here is a solid-state NMR investigation of the so-called “colossal expansion” material, Ag3Co(CN)6, a compound that exhibits some of the largest positive and negative thermal expansion properties reported. This study explores the 13C, 15N, and 59Co NMR properties of this material at room temperature and at variable temperatures with the goal of probing the effects of this colossal expansion behaviour on these properties. We found that the flexible nature of the crystal framework leads to a distribution of electric field gradients, and that, oddly enough, no strong correlation is observed between the NMR parameters of Ag3Co(CN)6 and its colossal expansion nature. The 59Co isotropic chemical shift increased and the 59Co nuclear quadrupolar coupling constant decreased with increasing temperature, but neither of these relationships were extraordinary when compared to other octahedral Co(III) complexes. The link between the colossal expansion and the NMR properties of Ag3Co(CN)6 may be the distribution of lattice parameters and hence unusually broad features in the 59Co NMR spectra. The high order of symmetry at the cobalt site resulted in a small quadrupolar coupling constant less than 1 MHz in magnitude. We also observed a |1J(107/109Ag,15N)| value of 96 Hz, the largest 107/109Ag–15N coupling constant reported to date.

scholarly journals Spying on the boron–boron triple bond using spin–spin coupling measured from 11B solid-state NMR spectroscopy

2015 ◽  
Vol 6 (6) ◽  
pp. 3378-3382 ◽  
Author(s):  
Frédéric A. Perras ◽  
William C. Ewing ◽  
Theresa Dellermann ◽  
Julian Böhnke ◽  
Stefan Ullrich ◽  
...  
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Solid State Nmr ◽  
Triple Bond ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Solid State Nmr Spectroscopy ◽  
Spin Spin Coupling ◽  
Insight Into

Boron–boron J coupling constants provide new insight into the nature of the boron–boron triple bond.

Structure of an aluminophosphate EMM-8: a multi-technique approach

2007 ◽  
Vol 63 (1) ◽  
pp. 56-62 ◽  
Author(s):  
Guang Cao ◽  
Mobae Afeworki ◽  
Gordon J. Kennedy ◽  
Karl G. Strohmaier ◽  
Douglas L. Dorset
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Solid State Nmr ◽  
Structural Information ◽  
Local Symmetry ◽  
Unit Cell ◽  
Local Environments ◽  
Synchrotron Powder Diffraction ◽  
The Relationship

The crystal structure of an aluminophosphate, EMM-8 (ExxonMobil Material #8), was determined in its calcined, anhydrous form from synchrotron powder diffraction data using the computer program FOCUS. A linkage of double four-ring (D4R) building units forms a two-dimensional framework with 12-MR and 8-MR channels, and differs from a similar SAPO-40 (AFR) framework only by the relationship between paired D4R units. Rietveld refinement reveals a fit of the model to the observed synchrotron data by R wp = 0.1118, R(F 2) = 0.1769. Local environments of the tetrahedral phosphorus and aluminium sites were established by solid-state NMR, which detects distinct differences between as-synthesized and calcined materials. Distinct, reversible changes in the local symmetry of the P and Al atoms were observed by NMR upon calcination and subsequent hydration. These NMR data provided important constraints on the number of tetrahedral (T) atoms per unit cell and the connectivities of the T atoms. Detailed local structural information obtained by solid-state NMR thereby guided the ultimate determination of the structure of AlPO EMM-8 from the powder data. Comparisons are made to the recently published crystal structure of the fluoride-containing, as-synthesized SSZ-51, indicating that the unit-cell symmetry, axial dimensions and framework structure are preserved after calcination.

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