Roesky'S Ketone: A Spectroscopic Study

We present a joint experimental-theoretical spectroscopic study of 5-oxo-1,3,2,4-dithiadiazole, also known as Roesky's ketone. The theoretical results of a vibrational analysis, calculated at the DFT/B3LYP/6-311+G* level of theory, of the title compound have been compared with experimental data, consisting of Raman and IR frequencies in different phases, and the bands have been assigned to the normal vibrations of the molecule. Additionally, an analysis of the origin of the high intensity of the band assigned to the CO stretching mode was performed based on calculated stockholder charges and atomic dipoles. The results of theoretical calculations of the C-13 and N-14 NMR chemical shifts are compared to experimentally obtained shifts.