ISSN:
0749-1581
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Proton spin-lattice relaxation rates (R1 values) have been measured at 400 MHz for a series of substituted aromatic compounds to determine the steric effects of ortho substituents on the R1 values of the methyl groups. These values have been interpreted on the basis of differences in the barriers to methyl group rotation caused by the substituent, resulting in changes in the contributions from the dipolar and the spin-rotation relaxation mechanisms. A significant dynamic range of methyl R1 values has been observed, showing that these measurements are sensitive to the steric environment.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrc.1260230803