ChemInform Abstract: Tyrosyl Motion in Peptides: 2H NMR Line Shapes and Spin-Lattice Relaxation.

ChemInform ◽  
1987 ◽  
Vol 18 (30) ◽  
Author(s):  
D. M. RICE ◽  
Y. C. MEINWALD ◽  
H. A. SCHERAGA ◽  
R. G. GRIFFIN
Keyword(s):  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
2H Nmr ◽  
Spin Lattice ◽  
Line Shapes

2H NMR Line Shapes and Spin−Lattice Relaxation in Ba(ClO3)2·2H2O

1997 ◽  
Vol 101 (6) ◽  
pp. 988-994 ◽  
Author(s):  
Joanna R. Long ◽  
Rainer Ebelhäuser ◽  
R. G. Griffin
Keyword(s):  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
2H Nmr ◽  
Spin Lattice ◽  
Line Shapes

Anisotropic 2H-NMR spin-lattice relaxation in oriented bilayers of DMPC and DMPC + cholesterol

1992 ◽  
Vol 89 ◽  
pp. 237-242 ◽  
Author(s):  
MA Krajewski-Bertrand ◽  
Y Nakatani ◽  
G Ourisson ◽  
EJ Dufourc ◽  
A Milon
Keyword(s):  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
2H Nmr ◽  
Spin Lattice

NMR Studies of the Order and Dynamics of Dipalmitoylphosphatidylchoiine Bilayers as a Function of Pressure

1996 ◽  
Author(s):  
Ana Jonas ◽  
Xiangdong Peng
Keyword(s):  
Liquid Crystalline ◽  
Relaxation Times ◽  
Lateral Diffusion ◽  
Lattice Relaxation ◽  
Pressure Effects ◽  
Spin Lattice Relaxation ◽  
2H Nmr ◽  
Spin Lattice ◽  
Spin Locking ◽  
Nmr Methods

We have used 2H NMR methods to examine the order and dynamics of dipalmitoylphosphatidylcholine (DPPC) in multilamellar and small unilamellar vesicles in water as a function of pressure. Multipulse 2H NMR techniques were used with selectively deuterated DPPC on both chains at positions C-2, C-9, or C-13, to obtain lineshapes, spin-lattice relaxation times (T1), and spin-spin relaxation times (T2) at 50 °C from 1 bar to 5.2 kbar pressure. This pressure range allowed us to explore the phase behavior of DPPC from the liquid crystalline (LC) phase through various gel phases (Gl, Gll, Glll, GX), including the interdigited Gi phase. Pressure has an ordering effect: on all chain segments in all the phases. In the LC phase, the order parameter (SCD) decreases from C-2 > C-9 > C-13, while in the gel phases SCD decreases from C-9 > C-13 > C-2, indicating that in the gel phases the middle segments of the chains are more restricted in their motions than the ends. In the LC phase, T1 and T2 values for all segments decrease with pressure and have an order from C-13 > C-9 > C-2. These results suggest that similar conformational motions and molecular rotational motions occur in the LC state in all segments, but have increased amplitudes and frequencies toward the methyl ends. At the phase transitions, discontinuities and abrupt reversal of the slopes for the T1 or T2 dependences on pressure indicate major changes in motional modes and rates for DPPC molecules in the different structures. In the second part of this study, we have measured the lateral diffusion of DPPC in sonicated vesicles in D2O as a function of pressure. The spin-lattice relaxation rate in the rotating frame T−11p was plotted as a function of the square root of the spin-locking field angular frequency (ω1)1/2, and the lateral diffusion coefficient (D) was calculated from the slope. Pressure effects are observed on lateral diffusion in the LC phase (D = 5.4 − 2 × 10−9 cm2 seconds, from 1 to 300 bar) but are negligible in the GI phase (D ≈ 1.0 × 10−9 cm2 seconds, from 400 to 800 bar).

Deuterium NMR Study of the Solid-Solid Phase Transition in Phenethylammonium Bromide

1991 ◽  
Vol 46 (8) ◽  
pp. 691-696 ◽  
Author(s):  
Marco L. H. Gruwel ◽  
Roderick E. Wasylishen
Keyword(s):  
Phase Transition ◽  
Low Temperature ◽  
Line Shape ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Temperature Phase ◽  
Spin Lattice ◽  
H Nmr ◽  
Line Shapes ◽  
Low Temperature Phase

AbstractUsing 2H NMR, the dynamics of the cation in phenethylammonium bromide were studied in the two solid phases. Line shape and spin-lattice relaxation rate studies of the ammonium headgroups and the adajacent methylene groups indicate the onset of alkyl-chain motion prior to the first order phase transition. In the low-temperature phase the line shape and the spin-lattice relaxation rates of the -ND3 groups are consistent with C3 jumps and an activation energy of 54±4 kJ mol-1. However, in the high-temperature phase the spin-lattice relaxation studies indicate the presence of small-angle diffusion of the -ND3 groups around the C3 symmetry axis. In this phase the -CD2- groups show line shapes typical of large-amplitude two-site jumps occurring at a rate > 107 s-1 . In the low-temperature phase, at temperatures below 295 K, the -CD2- 2H NMR line shapes indicate that the C - D bonds are essentially static

Anisotropic spin-lattice relaxation in lipid bilayers: A solid state 2H NMR lineshape study

1985 ◽  
Vol 119 (2-3) ◽  
pp. 251-255 ◽  
Author(s):  
D.J. Siminovitch ◽  
M.J. Ruocco ◽  
E.T. Olejniczak ◽  
S.K. Das Gupta ◽  
R.G. Griffin
Keyword(s):  
Solid State ◽  
Lipid Bilayers ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
2H Nmr ◽  
Spin Lattice

Protonenresonanzuntersuchungen über innermolekulare Bewegungen, Phasenumwandlungen und Entglasungsvorgänge in festen Äthern

1966 ◽  
Vol 21 (8) ◽  
pp. 1231-1240 ◽  
Author(s):  
K. Grude ◽  
J. Haupt ◽  
W. Müller-Warmuth
Keyword(s):  
Solid State ◽  
Melting Point ◽  
Lattice Relaxation ◽  
Relaxation Mechanism ◽  
Lattice Relaxation Time ◽  
Spin Lattice Relaxation ◽  
Small Range ◽  
Second Moment ◽  
Spin Lattice ◽  
Line Shapes

Proton magnetic resonance investigations on solid dimethylether (DM) , diethylether (DE) , dipropylether (DP), diisopropylether (DIP), dibutylether (DB), dimethoxymethane (DMM), diethoxymethane (DEM), dimethoxyethane (DME), diethoxyethane (DEE), acetaldehyde (ACA) and diethylketone (DEK) yielded information on molecular motion, solid state phase transitions and deglassing processes. The temperature-dependence of the spin-lattice relaxation time and the second moment was studied between the melting point and 77 °K using radiofrequency pulse techniques. Both spin-lattice relaxation and line shapes are governed by dipolar interactions which are modulated in time by hindered rotations of CH3-groups. The parameters for this relaxation mechanism are given in detail. Concerning the general results it was possible to distinguish between three cases : a) substances that form only one crystalline phase in the solid state (DM, DIP, DEM, DME, ACA, and DEK); b) ethers that form only a vitreous state (DP and DEE) and c) ethers that form both crystalline and vitreous states depending on the way in which the liquid was cooled. In the last case a pronounced decrease of the second moment of the absorption line was observed near the phase transition from the vitreous to the polycrystalline state. This means that within a small range of temperatures far below the melting point some kind of melting of the glass occurs before the crystal is formed.

A multinuclear nuclear magnetic resonance study of methylammonium nitrate

1986 ◽  
Vol 64 (4) ◽  
pp. 773-776 ◽  
Author(s):  
Roderick E. Wasylishen
Keyword(s):  
Symmetry Axis ◽  
Lattice Relaxation ◽  
Nuclear Magnetic Resonance Study ◽  
Spin Lattice Relaxation ◽  
Magnetic Resonance Study ◽  
Strongly Coupled ◽  
Spin Lattice ◽  
Line Shapes ◽  
Liquid Phases ◽  
Plastic Phase

Deuterium nmr line shapes in the solid II phase of methylammonium nitrate (MAN) indicate that motion of the cation is restricted to internal rotations of the ND3 group about the C—N axis. In the high temperature plastic phase, solid I, of MAN, 2H, 14N, and 17O nmr results demonstrate that both the cation and anion undergo rapid overall rotations that result in complete averaging of all nuclear quadrupolar interactions. Spin-lattice relaxation results imply that rotations of the cation and anion are anisotropic and that the overall rotations are strongly coupled in both the solid I and liquid phases. At the melting point, overall rotations of the cation are only slightly faster in the liquid phase than in the solid I phase. In the solid I phase, in-plane rotations of the nitrate ion are about twice as rapid as end-over-end rotations of the C3 axis. In the neat liquid, rotations of the NO3− ion are more isotropic, with overall rotations being slightly faster than rotations about the symmetry axis.

Deuteron Magnetic Resonance in a-Si and a-SiGe Produced from Fluorides

1986 ◽  
Vol 70 ◽  
Author(s):  
V. P. Bork ◽  
P. A. Fedders ◽  
R. E. Norberg ◽  
D. J. Leopold ◽  
K. D. Mackenzie ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Resonance Line ◽  
Relaxation Times ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Weakly Bound ◽  
Spin Lattice ◽  
Line Shapes ◽  
Quadrupolar Doublet

ABSTRACTDeuteron magnetic resonance line shapes and spin lattice relaxation times are presented for a-Si:D, F and a-SiGe:D, F. These parameters differ from those for typical a-Si:D, H samples, but in some respects are similar to those for an annealed a-Si:D, H sample. The a-SiGe:D, F spectra display an unusually large broad central weakly bound D resonance component and a barely-resolved Ge-D quadrupolar doublet. Comparisons indicate substantial differences in void morphology between the a-Si:D, F and a-SiGe:D, F.

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