Intramolecular hydrogen bonds: ab initio Car–Parrinello simulations of arylamide torsions

详细信息	查看全文 | 推荐本文 |

• 作者：Doerksen ; Robert J. ; Chen ; Bin ; Klein ; Michael L.
• 刊名：Chemical Physics Letters
• 出版年：2003
• 期刊代码：7_00092614
• 类别：ph
• 出版时间：October 13, 2003
• 卷：380
• 期：1-2
• 页码：150-157
• 文件大小：411 K

摘要

Gas-phase, room temperature Car–Parrinello molecular dynamics simulations using the HCTH density functional are reported for the arylamides acetanilide (1) and ortho-methylthioacetanilide (2). The simulations show that in 1, rotation around the ring–amide bond is relatively unrestricted. By contrast, in 2 the methylthio side chain encourages the amide to be directed with N–H pointing toward S, not to flip by 360°, and furthermore to remain close to coplanar with the benzene ring. Because of an intramolecular N–HS hydrogen bond, the N–H stretch frequency of 2 is red-shifted by 78 cm⁻¹ compared to that of 1.