Petrov Vjacheslav, Petrova Valentina, Girichev Georgiy V, Oberhammer Heinz, Giricheva Nina I, Ivanov Sergey
Ivanovo State University, Ivanovo 153025, Russia.
J Org Chem. 2006 Apr 14;71(8):2952-6. doi: 10.1021/jo0524270.
The molecular structure and conformational properties of benzenesulfonamide, C6H5SO2NH2, were studied by gas electron diffraction (GED) and quantum chemical methods (MP2 and B3LYP with different basis sets). The calculations predict the presence of two stable conformers with the NH2 group eclipsing or staggering the SO2 group. The eclipsed form is predicted to be favored by about 0.5 kcal/mol. According to GED, the saturated vapor over solid benzenesulfonamide at a temperature of 150(5) degrees C consists of the eclipsed conformer. The GED intensities, however, possess a very low sensitivity toward the vapor composition, and contributions of the anti conformer of up to 75% (at the 0.05 level of significance) or up to 55% (at the 0.25 level of significance) cannot be excluded. The molecule possesses C(sS) symmetry with the S-N bond perpendicular to the ring plane.
通过气体电子衍射（GED）和量子化学方法（采用不同基组的MP2和B3LYP）研究了苯磺酰胺（C6H5SO2NH2）的分子结构和构象性质。计算预测存在两种稳定构象异构体，其中NH2基团与SO2基团呈重叠或交叉排列。预测重叠形式比交叉形式更稳定，能量差约为0.5千卡/摩尔。根据GED结果，在150(5)摄氏度下，固体苯磺酰胺上方的饱和蒸气由重叠构象异构体组成。然而，GED强度对蒸气组成的敏感度非常低，不能排除反式构象异构体的贡献高达75%（在0.05显著性水平）或高达55%（在0.25显著性水平）。该分子具有C(sS)对称性，S-N键垂直于环平面。
