Rotational barriers in 1-dimethylamino-3-dimethyliminio-2-(para-substituted phenyl)propene perchlorates

Abstract

The barriers to internal rotation about the C–N bonds in 1-dimethylamino-3-dimethyliminio-2-(para- substituted phenyl)propene perchlorates are not sensitive to the conjugative effects due to change in the para-substituent (H, Me, Cl, OMe, NO₂, and CN), consistent with the reported invariance of the u.v. absorption characteristics of these systems for a similar change in the electronic effects on the phenyl group.