Normal coordinate analyses of molecules with the amide group

Abstract

Normal coordinate analyses have been performed on molecules with the amide group using force constants transferred from N-methylacetamides and polyamides. The molecules involved were hexamethylenedipropionamide, N,N'-dihexyladipamide, N,N'-dihexylsebacamide, some N-alkylamides, and some C-deuterated derivatives of nylon 66. In some molecules the dependence of frequencies on torsion angles about C-C(=O) or N-C(=H2) was studied. Dispersion curves were obtained for nylon 6 and nylon 66. The agreement between observed and calculated frequencies is good in most cases, and a complete or nearly complete assignment of infrared frequencies has been established.