ISSN:
0749-1581
Keywords:
2,4-Dicyclohexyl-2-methylpentane
;
Traction fluids
;
13C NMR
;
Molecular dynamics
;
Relaxation times
;
NOE factors
;
Relaxation models
;
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
An extensive investigation has been made of the 13C NMR relaxation parameters of 2,4-dicyclohexyl-2-methylpentane neat and in solution. Spin-lattice relaxation times and nuclear Overhauser enhancements were measured as a function of temperature, concentration and radiofrequency. The results for all the carbons, except the methyls, can be interpreted by using a reduced spectral density which suggests that there is an isotropically rotating semi-rigid backbone structure whose internal librations and vibrations reduce the amplitude of the spectral density. However, interpretation of the methyl group data required the addition of a discrete correlation time characteristic of the internal motion about a C3 axis. From dilution studies, the validity of using the two-correlation time spectral density with S2 = 0 when the rate of overall motion approaches that of the internal motion was established, for the first time.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1260280215
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