Infrared Spectrophotometric Differences Between Some Substituted Anilines and Their Hydrochlorides
The ortho- and paraphenylenediamines, aminophenols, and their hydrochlorides and para-anisidine and the hydrochlorides of ortho- and paraanisidine were studied primarily in the regions 2.7–4μ and 5.7–8μ. All the materials were prepared in KBr disks in concentrations of the order of 1–2 · 106 M. Ordinate expansion was used to give full-scale deflection. The order of the extent of hydrogen bonding, as determined by the shift in the N-H stretching frequencies as well as C-N absorption, is anisidine < phenylenediamine < aminophenol. The aromatic vibrations are modified in the same sequence.