Molecular Conformation of Aza-substituted Benzanilides by Electronic Absorption Spectra and Dipole Moments

The electronic absorption spectra of thirteen pyridine aromatic amides of general formula R1-CO-NH- R2 (Ri, R2 = pyridil or phenyl) were obtained in methanol and dioxane solution. The band assignment is briefly discussed. The dipole moments were measured in dioxane at 25 ± 0.1 °c and compared with values calculated by both the S. H. M. 0. method and vectorial model. The comparison suggests the most probable conformation of derivatives which have the nitrogen either in the ortho or meta position in one or both rings of the molecule