scholarly journals Synthesis and variable temperature NMR study of glucose based 1,2,3-triazole

2020 ◽  
Author(s):  
Rasha Saad Jwad
Keyword(s):  
Variable Temperature ◽  
Nmr Study

scholarly journals Variable-Temperature Multinuclear Solid-State NMR Study of Oxide Ion Dynamics in Fluorite-Type Bismuth Vanadate and Phosphate Solid Electrolytes

2019 ◽  
Vol 31 (5) ◽  
pp. 1704-1714 ◽  
Author(s):  
Matthew T. Dunstan ◽  
David M. Halat ◽  
Matthew L. Tate ◽  
Ivana Radosavljevic Evans ◽  
Clare P. Grey
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Solid Electrolytes ◽  
Variable Temperature ◽  
Bismuth Vanadate ◽  
Ion Dynamics ◽  
Nmr Study ◽  
Fluorite Type ◽  
Oxide Ion

ChemInform Abstract: A VARIABLE TEMPERATURE NMR STUDY OF CARBONYLDIPHENYLACETYLENE TRIS(PI-CYCLOPENTADIENYLRHODIUM) AND ITS BIS(PENTAFLUOROPHENYL)DERIVATIVE

1973 ◽  
Vol 4 (48) ◽  
pp. no-no
Author(s):  
T. YAMAMOTO ◽  
A. R. GARBER ◽  
G. M. BODNER ◽  
L. J. TODD ◽  
M. D. RAUSCH ◽  
...  
Keyword(s):  
Variable Temperature ◽  
Nmr Study

Nuclear magnetic resonance studies of the methylammonium hexahalotellurates

1992 ◽  
Vol 70 (3) ◽  
pp. 849-855 ◽  
Author(s):  
Mark R. MacIntosh ◽  
Marco L. H. Gruwel ◽  
Katherine N. Robertson ◽  
Roderick E. Wasylishen
Keyword(s):  
Line Shape ◽  
Nmr Spectra ◽  
Room Temperature ◽  
Solid Phase ◽  
Variable Temperature ◽  
Spin Lattice Relaxation ◽  
Temperature Phase ◽  
H Nmr ◽  
Nmr Study ◽  
Correlated Motion

A 2H and 14N NMR study of the solid methylammonium hexahalotellurates, (MA)2TeX6 (MA = CH3ND3+ or CD3NH3+, X = Cl, Br, and I), has been undertaken to characterize the dynamics of the methylammonium (MA) ion as a function of temperature. At room temperature, the MA ion in the hexachlorotellurate (solid II) is confined to C3 jumps about the C—N axis while a small angle libration of the C—N axis is occurring. In the room temperature phase, solid I, of (MA)2TeBr6 and (MA)2TeI6 the MA ions are performing overall reorientations on the ps time scale, averaging the 2H nuclear quadrupolar interactions to zero. Variable temperature 2H NMR spin-lattice relaxation times, T1, indicate an activation energy, EA, for "isotropic" reorientations of the CH3ND3+ ion of 5.2 ± 0.5 and 2.6 ± 0.3 kJ mol−1 for X = Br and I, respectively. Deuterium T1 values for C-deuterated MA ion in the hexaiodotellurate indicate an EA for whole-ion reorientation of 3.1 ± 0.3 kJ mol−1. At any given temperature, the correlation time, τc, derived from the T1 results was found to be the same for the two deuterium-labelled hexaiodotellurates. The similarity of both the EA and the τc values implies correlated motion of the methyl and ammonium groups. The 14N T1 results for solid I of (MA)2TeI6 indicate that C—N axis motions, with an EA = 5.6 ± 0.6 kJ mol−1, are more hindered than N—D or C—D bond dynamics. The 2H NMR spectra for (MA)2TeI6 (solid II) and (MA)2TeBr6 (solids II, III, and IV) are characterized by a Pake doublet line shape. The measured peak-to-peak splittings are less than what is predicted by C3 motion about the molecular symmetry axis. It is possible to model these line shapes by postulating that C3 rotations of the methyl and ammonium groups occur as the C—N axis librates in an effective cone about the position of the static molecular axis. For (CH3ND3)2TeBr6 and (CD3NH3)3TeBr6 the peak-to-peak splittings in the 2H NMR spectra were measured as a function of temperature in solid phases II, III, and IV and were found to be similar. Finally, the 2H NMR line shape relaxation for (MA)2TeBr6 (solid III) displays an orientation dependence indicating that rotations about the C—N axis are discrete rather than diffusive in nature. For solid phase II of (MA)2TeCl6, the line shape is observed to relax isotropically, implying that continuous C3 rotations are taking place. Keywords: 2H and 14N NMR, methylammonium hexahalotellurates, molecular motion.

scholarly journals NMR study of Li distribution in Li7−xHxLa3Zr2O12 garnets

2015 ◽  
Vol 3 (10) ◽  
pp. 5683-5691 ◽  
Author(s):  
G. Larraz ◽  
A. Orera ◽  
J. Sanz ◽  
I. Sobrados ◽  
V. Diez-Gómez ◽  
...  
Keyword(s):  
Variable Temperature ◽  
Temperature Measurements ◽  
Dynamic Processes ◽  
Relative Population ◽  
Nmr Study

We present a NMR investigation of 6Li7−xHxLa3Zr2O12 (0 ≤ x ≤ 5) garnets to study the distribution of Li ions. The facile H+/Li+ exchange alters the relative population of Li sites, and allows the identification of 3 different bands ascribed to Li in different environments. Variable temperature measurements indicated the presence of dynamic processes between octahedral and tetrahedral Li sites.

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