Infrared and Raman group frequency correlations: Substituted oxamides

Abstract

Infrared and Raman spectra of N,N′-dialkyl oxamides and N,N′-diaryl oxamides or ( N,N′-oxanilides) were recorded, and characteristic group frequencies useful in spectra-structure identification are presented. The i.r. and Raman data recorded for N,N′-dialkyl or N,N′-diaryl oxamides in the solid phase can be explained on the basis that they exist in an intermolecularly hydrogen bonded trans configuration where each oxamide group can be viewed as having C 2 h symmetry. In the vapor phase, N,N′-dimethyloxamide also exists in the trans configuration. Evidence is presented that suggest N,N,N′,N′-tetraethyloxamide exists as rotational isomers in solution, and that these are the trans and gauche structures.