The EPR spectra of n-alkyl, 2-methylalky1, 2, 2-dimethylalkyl, 2, 2, 3-trimethylbutyl, and 2, 2, 3, 3-tetramethylbutyl radicals indicate that at 90 K they exist in “rigid” conformations with respect to rotation about the C,-C, bonds. The preferred conformations about the C,-C, and C,-C, bonds were deduced by analysis of the p-and yH hyperfine splittings (hfs). 2, 2, 3, 3- Tetramethylbutyl radicals, the only radicals with a CH3 group approximately all-trans with ...
[DiCosimo, Robert; Moore, Stephen S.; Sowinski, Allan F.; Whitesides, George M. Journal of the American Chemical Society, 1982 , vol. 104, # 1 p. 124 - 133]