Magnetic resonance in chemistry

Steric influences on spin??lattice relaxation rates of methyl protons in substituted aromatic molecules

WJ Chazin, LD Colebrook

Index: Chazin, Walter J.; Colebrook, Lawrence D. Magnetic Resonance in Chemistry, 1985 , vol. 23, # 7 p. 597 - 604

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Citation Number: 13

Abstract

Abstract Proton spin-lattice relaxation rates (R 1 values) have been measured at 400 MHz for a series of substituted aromatic compounds to determine the steric effects of ortho substituents on the R 1 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 ...