Infrared Spectra of Benzamide, its p-Substituted Derivatives, Pyridinecarboxylic Acid Amides and Pyrazinamide.

Abstract

Infrared absorption spectra of benzamide, p-substituted benzamide, pyridinecarboxylic acid amides, pyrazinamide and their homologs were measured in Nujol mull and in solution, and the assignment of the characteristic absorption has been made. The infrared absorption spectral data suggested the crystal structure of isonicotinamide, α-and β-type of pyrazinamide and β-type of pyrazinamide. 1) Benzamide, p-substituted benzamides, picolinamide (β-type), and pyrazinamide (β-type) showed a similar absorption tendency and are therefore supposed to have a similar crystal structure. β-Type of picolinamide and pyrazinamide is different in symmetric center. 2) Nicotinamide and isonicotinamide showed the same absorption tendency and, therefore, the same crystal structure was formed. 3) Pyrazinamide (α-type) and picolinamide (α-type) showed the same absorption tendency and is supposed to form the same crystal structure.