A spectroscopic study of the model urethanes

Article abstract of DOI:10.1016/0584-8539(94)80158-4

The synthesis, far infrared spectra, temperature-dependent mid-infrared spectra in the carbonyl and NH streching regions and the Fourier transform Raman spectra are reported for polycrystalline samples of three small diurethanes, 1,3-phenyl di(carbamic acid methyl ester), 2,6-toluene di(carbamic acid methyl ester) and 2,4-toluene di(carbamic acid methyl ester).An ab initio geometry optimization is reported for methyl N-phenyl carbamate using STO-3G and 3-21G basis sets, and for the three small diurethanes by molecular machanics methods using the Dreiding I force field.The results suggest that, in isotropic surroundings, only a very small number of the 256 posible conformers of the urethane groups in the three small diurethanes contribute appreciably to the structure.