Peptide conformations. 15. One- and two-dimensional proton, carbon-13 and nitrogen-15 NMR studies of cyclo(Pro-Phe-Gly-Phe-Gly)n (n = 1, 2): selective complexation of lithium ions (n = 1) and potassium ions (n = 2)

1982 ◽  
Vol 104 (17) ◽  
pp. 4534-4540 ◽  
Author(s):  
Horst Kessler ◽  
Wolfgang Hehlein ◽  
Regina Schuck
Keyword(s):  
Potassium Ions ◽  
Two Dimensional ◽  
Nmr Studies ◽  
Lithium Ions ◽  
Peptide Conformations ◽  
Selective Complexation

Nuclear magnetic resonance (NMR) studies of sintering effects on the lithium ion dynamics in Li1.5Al0.5Ti1.5(PO4)3

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Edda Winter ◽  
Philipp Seipel ◽  
Tatiana Zinkevich ◽  
Sylvio Indris ◽  
Bambar Davaasuren ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Lithium Ion ◽  
Magic Angle Spinning ◽  
Spin Lattice Relaxation ◽  
Magic Angle ◽  
Nmr Studies ◽  
Lithium Ions ◽  
Jump Dynamics ◽  
Nuclear Magnetic

Abstract Various nuclear magnetic resonance (NMR) methods are combined to study the structure and dynamics of Li1.5Al0.5Ti1.5(PO4)3 (LATP) samples, which were obtained from sintering at various temperatures between 650 and 900 °C. 6Li, 27Al, and 31P magic angle spinning (MAS) NMR spectra show that LATP crystallites are better defined for higher calcination temperatures. Analysis of 7Li spin-lattice relaxation and line-shape changes indicates the existence of two species of lithium ions with clearly distinguishable jump dynamics, which can be attributed to crystalline and amorphous sample regions, respectively. An increase of the sintering temperature leads to higher fractions of the fast lithium species with respect to the slow one, but hardly affects the jump dynamics in either of the phases. Specifically, the fast and slow lithium ions show jumps in the nanoseconds regime near 300 and 700 K, respectively. The activation energy of the hopping motion in the LATP crystallites amounts to ca. 0.26 eV. 7Li field-gradient diffusometry reveals that the long-range ion migration is limited by the sample regions featuring slow transport. The high spatial resolution available from the high static field gradients of our setup allows the observation of the lithium ion diffusion inside the small (<100 nm) LATP crystallites, yielding a high self-diffusion coefficient of D = 2 × 10−12 m2/s at room temperature.

Two-dimensional solid-state NMR studies of crystalline poly(ethylene oxide): Conformations and chemical shifts

Polymer ◽  
2005 ◽  
Vol 46 (25) ◽  
pp. 11737-11743 ◽  
Author(s):  
D.J. Harris ◽  
T.J. Bonagamba ◽  
M. Hong ◽  
K. Schmidt-Rohr
Keyword(s):  
Solid State ◽  
Ethylene Oxide ◽  
Solid State Nmr ◽  
Chemical Shifts ◽  
Two Dimensional ◽  
Nmr Studies ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

Two dimensional NMR studies on Megasphaera elsdenii

1987 ◽  
pp. 271-274
Author(s):  
Carlo van Mierlo ◽  
Jacques Vervoort ◽  
Franz Miiller
Keyword(s):  
Two Dimensional ◽  
Nmr Studies ◽  
Megasphaera Elsdenii
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