An alternative gas-phase electron diffraction and quantum chemical study of nitroethane

The results of alternative gas-phase electron diffraction (GED) study of nitroethane are compared with those reported in the previous study by Tarasov et al. [1]. A fairly large reliability factor (R = 6.1%) obtained in that work, even though the intensity data over the range s > 27 Å−1 were excluded from the analysis, was one of the reasons for undertaking this investigation. Our structural analysis was performed with electron diffraction patterns used by Tarasov et al. In this work, various quantum chemical models were used as initial approximations, and two sets of GED data equally well fitted to theory were obtained. For the experimental intensity curve in the range of s = 3.8-32.6 Å−1, the disagreement between the theoretical and experimental data reached R = 4.3%. The natural bond orbital (NBO) analysis and the quantum theory of atoms in molecules (QTAIM) were used to reveal the reasons of a low barrier to rotation of nitro group.