On the Role of Nuclear Spin Symmetry of Symmetric Top Molecules in Gas Phase Nuclear Magnetic Relaxation

1974 ◽  
Vol 52 (5) ◽  
pp. 387-395 ◽  
Author(s):  
B. C. Sanctuary
Keyword(s):  
Nuclear Spin ◽  
Magnetic Relaxation ◽  
Spin Symmetry ◽  
Nuclear Magnetic Relaxation ◽  
The Difference ◽  
Symmetric Top Molecules ◽  
Spin Species ◽  
Zero Frequency ◽  
Nuclear Magnetic

For symmetric top molecules the role of nuclear spin symmetry is included in the derivation of the nuclear magnetic relaxation rate. It is assumed that this is dominated by a spin-rotation mechanism. Of the three nuclear spin species which exist for ZX3Y' symmetric tops, it is found that the "zero frequency" K = −1 to +1 term results in two of the species relaxing with a different rate from the third. The difference, which allows a direct NMR evaluation of the relative values of [Formula: see text] and [Formula: see text], is enhanced at low temperatures.

scholarly journals Nuclear magnetic relaxation studies of the role of the metal ion in Mn2+-substituted aminoacylase I

1990 ◽  
Vol 188 (1) ◽  
pp. 175-180 ◽  
Author(s):  
Dirk HEESE ◽  
Stefan BERGER ◽  
Klaus-Heinrich ROHM
Keyword(s):  
Magnetic Relaxation ◽  
Metal Ion ◽  
Nuclear Magnetic Relaxation ◽  
Relaxation Studies ◽  
Nuclear Magnetic

Kinetic Theory of Nuclear Magnetic Relaxation of Polyatomic Molecules

1975 ◽  
Vol 53 (7) ◽  
pp. 707-722 ◽  
Author(s):  
B. C. Sanctuary ◽  
R. F. Snider
Keyword(s):  
Magnetic Relaxation ◽  
Degrees Of Freedom ◽  
Point Group ◽  
Relaxation Times ◽  
Spin Symmetry ◽  
Nuclear Magnetic Relaxation ◽  
Group Symmetry ◽  
Rotating Frame ◽  
Rotational Degrees Of Freedom ◽  
Nuclear Magnetic

Nuclear magnetic relaxation of polyatomic gases is discussed in terms of a Boltzmann equation. Weak intramolecular coupling is used to obtain formal expressions for the spin relaxation times and the chemical shift. In particular, restrictions arising from spin symmetry and from molecular point group symmetry are included.In carrying out the weak coupling calculation, it is necessary to approximate the time dependence of the rotational degrees of freedom. Here this is done with the aid of the 'rotating frame approximation', that is, all polarizations in the gas rotate in phase with the spins. This approximation is discussed from several points of view, including a mathematical discussion for a particular example. Finally the rotating frame approximation is related to the memory effects of general relaxation theory.

Nuclear magnetic relaxation in porous media: The role of the mean lifetime τ(ρ,D)

1991 ◽  
Vol 44 (10) ◽  
pp. 4960-4973 ◽  
Author(s):  
David J. Wilkinson ◽  
David Linton Johnson ◽  
Lawrence M. Schwartz
Keyword(s):  
Porous Media ◽  
Magnetic Relaxation ◽  
Nuclear Magnetic Relaxation ◽  
Mean Lifetime ◽  
The Mean ◽  
Nuclear Magnetic

On the Intramolecular Quadrupole Mechanism of Nuclear Magnetic Relaxation in the Gas Phase

1973 ◽  
Vol 51 (23) ◽  
pp. 2488-2494 ◽  
Author(s):  
B. C. Sanctuary
Keyword(s):  
Gas Phase ◽  
Nuclear Spin ◽  
Magnetic Relaxation ◽  
Nuclear Magnetic Relaxation ◽  
Relaxation Rates ◽  
Nuclear Spins ◽  
Nuclear Quadrupole ◽  
Intramolecular Mechanism ◽  
Nuclear Magnetic

By use of a nuclear quadrupole intramolecular mechanism, expressions are obtained for the relaxation rates for both ortho and para X2 molecules which have nuclear spins I1 > 1/2. It is found, except for I1 = 1, that as a result of the nuclear spin weightings the two species relax with different rates, even at temperatures high enough so that the rotational averages are approximately equal.

Nuclear magnetic relaxation in semiconductors

Physica ◽  
1954 ◽  
Vol 3 (7-12) ◽  
pp. 1130-1133
Author(s):  
N BLOEMBERGEN
Keyword(s):  
Magnetic Relaxation ◽  
Nuclear Magnetic Relaxation ◽  
Nuclear Magnetic
Sign in / Sign up

Export Citation Format

Share Document