On the Electronic Structure of the Carbonyl and the Amide Groups

Abstract (1) Electronic structures of carbonyl and amide groups were investigated by the use of the molecular orbital method; calculated values of resonance energy and π-electron densities may be regarded as reasonable compared with these which were observed. (2) Near ultraviolet absorption spectra were measured with acetone, acetylchloride, acetic acid, ethyl acetate and N-methylacetamide. As the result of these measurements, it becomes evident that the low intensity absorption band of acetone shifts to the side of shorter wave lengths when the methyl group of acetone is replaced Cl atom or OR and NR2 groups. These results can be explained by the present theoretical consideration if this absorption band is due to the n→π* transition.