Plots of observed rate of pseudo-first-order decay, kobs, versus concentration of tetrabutylammonium acetate for deprotonation of the radical cations of (open circles) N,N-dimethylaniline, 1c, and N,N,-dimethylaniline with (filled circles) a 4-methyl substituent, 1b, (filled squares) a 2-methyl substituent, 2, and (open squares) a 2-tert-butyl substituent, 3, in acetonitrile with 0.5 m water and 0.5 m tetramethylammonium perchlorate, at room temperature.

Brønsted plot of the logarithm of the bimolecular rate constant for deprotonation of the radical cations of N,N-dimethylaniline derivatives: (closed circles) 4-substituted-N,N-dimethylanilines, 1a-1e; (open circle) N,N,2-trimethylaniline, 2; (open squares) 2-tert-butyl-N,N-dimethylaniline, 3; and N,N,2,6-tetramethylaniline, 4.

Structures of Sterically Twisted N,N-Dimethylaniline Radical Cations, and the Dihedral Angles between the Planes Containing the Aromatic Ring and the Amino Nitrogen, θ.

Absorption spectra of the radical cations of (closed circles) N,N-dimethylaniline, 1c, and N,N,-dimethylaniline with (open circles) a 2-methyl substituent, 2, (closed squares) a 2-tert-butyl substituent, 3, and (open squares) 2,6-dimethyl substituents, 4, in acetonitrile containing 0.5 m water and 0.5 m tetrabutylammonium perchlorate, at room temperature.

Plot of the logarithm of the rate constant for unimolecular deprotonation (log(k-H )) versus the cosine squared of the dihedral angle θ, for the simple dimethylanilines, assumed to be appropriate for the intramolecular deprotonating anilines here.