Interpretation of β-Hydrogen Hyperfine Splittings in the Electron Spin Resonance of the 3-Methyl-3-phenylbut-1-yl Radical

Article abstract of DOI:10.1021/j150653a001

At low temperatures the PhCMe2CH2C^.H2 radical preferentially adopts a conformation in which the radical center and the phenyl substituent are gauche to each other when viewed along the C_β-C_γ bond.The β-hydrogens are magnetically nonequivalent and the magnitudes of their hyperfine splitting represent an average over rotation about the C_α-C_β bond.On the basis of the equation a^Hβ = 542 θ> G, we have derived a simple, two-component rotational potential which supports the suggestion that there is a weak, attractive interaction between the singly occupied C_α2p_z orbital and the ?-cloud of the phenyl substituent.The conformations of some related radicals are also discussed.