25Mg NMR determination of Knight shift, spin–lattice relaxation and electric field gradient in MgB2

2002 ◽  
Vol 124 (7) ◽  
pp. 269-273 ◽  
Author(s):  
T.J Bastow
Keyword(s):  
Electric Field ◽  
Electric Field Gradient ◽  
Field Gradient ◽  
Knight Shift ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Spin Lattice

scholarly journals Electric field Gradient Modulation by Motion of Lone-Pair Electrons in [(CH3)3S]2MCl6 (M = Pt, Sn) as a Possible Relaxation Mechanism of Chlorine Nuclear Quadrupole Resonance

1990 ◽  
Vol 45 (8) ◽  
pp. 1033-1037
Author(s):  
Makoto Kaga ◽  
Piotr Koziol ◽  
Tetsuo Asaji ◽  
Daiyu Nakamura
Keyword(s):  
Electric Field ◽  
Electric Field Gradient ◽  
Field Gradient ◽  
Complex Anion ◽  
Lone Pair ◽  
Lattice Relaxation ◽  
Relaxation Mechanism ◽  
Lattice Relaxation Time ◽  
Spin Lattice Relaxation ◽  
Lone Pair Electrons

AbstractThe temperature dependence of the chlorine NQR spin-lattice relaxation time T1Q was observed for trimethylsulfonium hexachlorometallates(IV), [(CH3)3S]2MCl6 (M = Pt, Sn), trimethylammonium hexachlorostannate(IV), [(CH3)3NH]2SnCl6, and tetramethylphosphonium hexachlorostannate(IV), [(CH3)4P]2SnCl6. The quadrupolar relaxation in [(CH3)3NH]2SnCl6 and [(CH3)4P]2SnCl6 can be described by the usual librational and reorientational motion of the complex anion at lower and higher temperatures, respectively. Besides T1Q due to these two mechanisms, T1Q minimum was observed at ca. 90 and 120 K for [(CH3)3S]2PtCl6 and [(CH3)3S]2SnCl6, respectively, which is attributable to the electric field gradient modulation by the motion of the [(CH3)3S]+ cation having lone-pair electrons. The activation energies for the isotropic reorientation of the complex anion were determined as 46, 65, 59, and 60 kJ mol -1 for [(CH3)4P]2SnCl6, [(CH3)2NH]2SnCl6, [(CH3)3S]2PtCl6, and [(CH3)3S]2SnCl6, respectively

Determination of chemical shift anisotropy tensor and molecular correlation time of proton pump inhibitor omeprazole by solid state NMR measurements

2020 ◽  
Vol 44 (44) ◽  
pp. 19393-19403
Author(s):  
Krishna Kishor Dey ◽  
Manasi Ghosh
Keyword(s):  
Correlation Time ◽  
Chemical Shift Anisotropy ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Spin Lattice Relaxation ◽  
Spin Lattice ◽  
Structure And Dynamics ◽  
Molecular Correlation ◽  
Anisotropy Tensor

The correlation between the structure and dynamics of omeprazole is portrayed by extracting CSA parameters through the 13C 2DPASS CP-MAS SSNMR experiment, site specific spin–lattice relaxation time by Torchia CP experiment, and calculation of the molecular correlation time.

An experimental evaluation of simplified procedures for determining the proton spin–lattice relaxation rates of natural products

1980 ◽  
Vol 58 (19) ◽  
pp. 2016-2023 ◽  
Author(s):  
Lawrence D. Colebrook ◽  
Laurance D. Hall
Keyword(s):  
Natural Products ◽  
Lattice Relaxation ◽  
Null Point ◽  
Proton Spin ◽  
Computational Method ◽  
Spin Lattice Relaxation ◽  
Relaxation Rates ◽  
Spin Lattice ◽  
Simplified Procedures

A general discussion is given of the determination of the proton spin–lattice relaxation rates of natural products, with particular emphasis on use of the null-point method which, for the systems studied here, gives identical results with those obtained via the conventional (and relatively time consuming) computational method.

Nuclear Spin Relaxation Investigations on the Influence of Impurities and Temperature on the Mean Free Path of Mobile Dislocations in Nacl

1980 ◽  
Vol 3 ◽  
Author(s):  
W. H. M. Alsem ◽  
J. Th. ◽  
M. De Hosson ◽  
H. Tamler ◽  
H. J. HackelÖEr ◽  
...  
Keyword(s):  
Free Path ◽  
Lattice Relaxation ◽  
Mean Free Path ◽  
Dislocation Motion ◽  
Spin Lattice Relaxation ◽  
Spin Lattice ◽  
Activation Rate ◽  
The Mean ◽  
Influence Of Impurities

ABSTRACTDislocation motion in alkali halide single crystals is strongly impeded by the presence of impurities, apart from obstacles built by the forest dislocations. The mean free path L of stepwise moving dislocations is measured by determination of the spin-lattice relaxation rate 1/T1ρ as a function of the strain rate έ, varying the content of impurities and the temperature. The latter influences the distribution of the point defects and the activation rate of dislocations before obstacles, while the former merely shorten L, thereby raising 1/T1ρ.

Sign in / Sign up

Export Citation Format

Share Document