Solid State NMR Relaxation and Hindered Rotations in Fully Asymmetric Local Environments

1993 ◽  
Vol 97 (11) ◽  
pp. 1457-1465 ◽  
Author(s):  
E. Knop ◽  
L. Latanowicz ◽  
E. C. Reynhardt
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Nmr Relaxation ◽  
Local Environments

Study of Polyethylene by Solid State NMR Relaxation and Spin Diffusion

1997 ◽  
Vol 30 (8) ◽  
pp. 2474-2481 ◽  
Author(s):  
R. R. Eckman ◽  
P. M. Henrichs ◽  
A. J. Peacock
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Spin Diffusion ◽  
Nmr Relaxation

scholarly journals High-Resolution Structural Insights into Bone: A Solid-State NMR Relaxation Study Utilizing Paramagnetic Doping

2012 ◽  
Vol 116 (38) ◽  
pp. 11656-11661 ◽  
Author(s):  
Kamal H. Mroue ◽  
Neil MacKinnon ◽  
Jiadi Xu ◽  
Peizhi Zhu ◽  
Erin McNerny ◽  
...  
Keyword(s):  
Solid State ◽  
High Resolution ◽  
Solid State Nmr ◽  
Nmr Relaxation ◽  
Relaxation Study ◽  
Structural Insights

scholarly journals Characterization of water in hydrated Bombyx mori silk fibroin fiber and films by 2H NMR relaxation and 13C solid state NMR

2017 ◽  
Vol 50 ◽  
pp. 322-333 ◽  
Author(s):  
Tetsuo Asakura ◽  
Kotaro Isobe ◽  
Shunsuke Kametani ◽  
Obehi T. Ukpebor ◽  
Moshe C. Silverstein ◽  
...  
Keyword(s):  
Solid State ◽  
Bombyx Mori ◽  
Silk Fibroin ◽  
Solid State Nmr ◽  
Nmr Relaxation ◽  
2H Nmr ◽  
Silk Fibroin Fiber ◽  
Bombyx Mori Silk

Investigation of Methyl Reorientations in 1,4-Dimethoxy- 2,6-dimethylbenzene by NMR and Inelastic Neutron Scattering

1979 ◽  
Vol 34 (5) ◽  
pp. 631-645 ◽  
Author(s):  
R. A. Wind ◽  
W. M. M. J. Bovée ◽  
J. C. F. Kupers ◽  
J. Smidt ◽  
Chr. Steenbergen
Keyword(s):  
Solid State ◽  
Neutron Scattering ◽  
Liquid State ◽  
Solid State Nmr ◽  
Inelastic Neutron Scattering ◽  
Nmr Relaxation ◽  
Inelastic Neutron ◽  
Methyl Groups ◽  
Methyl Group ◽  
Nmr Study

Abstract In this paper a solid state NMR relaxation study and inelastic neutron scattering (INS) experiments (the latter in the solid and liquid phase) are reported for a molecule containing methyl groups in different surroundings, namely 1,4-dimethoxy-2,6-dimethylbenzene. The results are compared with each other and with those of a liquid state NMR study reported earlier. It is found that in this way both the shapes and magnitudes of the various hindering potentials can be determined. The result is that the methyl groups 1, 2 and 4 possess a threefold cosine-shaped potential with heights given by 7.7, 9.0 and 15.0 kJ/mol according to the solid state NMR measurements (from the INS study the values 7.5, 7.5 and 16.0 kJ/mol were obtained). For methyl group 6 a mixture of a three-and six-fold symmetry had to be taken into account in order to explain the experiments. Except for methyl group 4 the liquid state NMR results deviate from those obtained with the other two techniques. A possible cause for this discrepancy is discussed. For the molecular structure it is concluded that the reorientations of the methyl groups 1 and 2 are influenced by mutual hindering and that the angle between the plane through the C4-O-C bond and the aromatic plane is small, whereas for the C1-O-C bond this angle is estimated to be about 70°.

Network Former Mixing (NFM) Effects in Ion-Conducting Glasses - Structure/Property Correlations Studied by Modern Solid-State NMR Techniques

2016 ◽  
Vol 6 ◽  
pp. 144-193 ◽  
Author(s):  
Hellmut Eckert
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Glass Structure ◽  
Energy Storage And Conversion ◽  
Structure Property ◽  
Local Environments ◽  
Ion Conducting ◽  
Multiple Network ◽  
Nmr Methods ◽  
Property Correlations

Glassy solid electrolytes are important integral components for all-solid-state devices for energy storage and conversion. The use of multiple network formers is an important part of their design strategy for specific applications. In many glass systems the interaction between the different network formers results in strongly non-linear variations in physical properties (network former mixing (NFM) effects), requiring a detailed understanding on a structural basis.The issues to be addressed involve both the structural organization and connectivities within the framework, the local environments and spatial distributions of the mobile ions, and the dynamical aspects of ion transport, to be discussed in relation to possible phase separation or nano-segregation effects. Besides Raman and X-ray photoelectron spectroscopies, solid state nuclear magnetic resonance (NMR) methods are particularly useful for providing detailed answers to such issues. The present review introduces the basic principles of modern solid state NMR methods and their applications to glass structure, with a particular focus on the characterization of network-former mixing effects in the most common lithium and sodium conducting oxide and chalcogenide glass systems. Based on the current state of the literature reviewed in the present work, some emerging general principles governing structure/property correlations are identified, to be tested by further experimenteation in the future.

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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