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Nuclear Spin-Lattice Relaxation Studies


Schmidt, Charles Frederick, Jr. (1974) Nuclear Spin-Lattice Relaxation Studies. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/d4e7-j132.


In order to study and better understand the microdynamic behavior of liquids, the nuclear spin-lattice relaxation rate has been measured and calculated for fluorine-19 in trifluoroacetic acid, and calculated for carbon-13 in toluene, carbondisulfide, benzene, methyl iodide, acetonitrile, and n-decane.

For fluorine in trifluoroacetic acid it is shown that the relaxation is controlled by the spin-internal-rotation interaction.

Spin-internal-rotation coupling is also shown to be important for carbon-13 relaxation of the methyl carbon of toluene, although intramolecular dipolar coupling also makes a significant contribution.

For carbon disulfide, it is shown that while the anisotropic chemical shift mechanism will contribute to the relaxation rate at superconducting magnetic fields, the spin-rotation interaction provides the dominant mechanism.

For benzene, it is shown that motion about the C6 symmetry axis can best be described using the inertial model. Intramolecular dipolar coupling is seen to be more important than spin-rotation coupling.

For methyl iodide and acetonitrile, it is shown that a description in which the motion is taken to be highly anisotropic gives good agreement with experiment.

In Part III, a description of the internal rotation for molecules containing alkane chains is given using the Rotational Isomeric State Approximation. The dynamics of the rotation implied by this model are analyzed, and the results are used to calculate carbon-13 spin-lattice relaxation rates for the methylene carbons. The model appears to be successful in predicting the relaxation time differences for the carbons at the methyl end of n-decanol.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Chemistry
Degree Grantor:California Institute of Technology
Division:Chemistry and Chemical Engineering
Major Option:Chemistry
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Chan, Sunney I.
Thesis Committee:
  • Chan, Sunney I. (chair)
Defense Date:3 August 1973
Funding AgencyGrant Number
Record Number:CaltechTHESIS:06242021-224248892
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:14289
Deposited By: Benjamin Perez
Deposited On:30 Jun 2021 17:08
Last Modified:30 Jun 2021 17:08

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