Theoretical study of the internal rotational barriers in nitrobenzene, 2-nitrotoluene, 2-nitrophenol, and 2-nitroaniline

摘要

The molecular geometries and internal rotational barriers of the nitro group of nitrobenzene (NB), 2-nitrotoluene (2-NT), 2-nitroaniline (2-NA), and 2-nitrophenol (2-NP) were calculated by five different types of density functional theory (DFT) methods with three different levels of basis sets. Analysis of the torsional angles of the nitro, methyl, amino, and hydroxyl groups indicate that NE, 2-NA, and 2-NP are planar molecules, but 2-NT is not a planar molecule. Internal rotational barriers of the nitro group were calculated as V-2 barriers, and the NO2 torsional potentials for each molecule were given. The values of the V2 barriers depend on the DFT methods and basis sets. The average values of the V2 barriers for NE, 2-NT 2-NA, and 2-NP are 6.47 kcal/mol, 3.00 kcal/mol, 10.20 kcal/mol, and 13.26 kcal/mol, respectively (C) 2001 John Wiley & Sons, Inc. [References: 28]