Density functional modelling studies on N-2-Methoxyphenyl-2-oxo-5-nitro-1-benzylidenemethylamine

Density functional calculations of the structure, molecular electrostatic potential and thermodynamic functions have been performed at B3LYP/6-31G(d) level of theory for the title compound of N-2-Methoxyphenyl-2-oxo-5-nitro-1-benzylidenemethylamine. To investigate the tautomeric stability, optimization calculations at B3LYP/6-31G(d) level were performed for the enol and keto forms of the title compound. Calculated results reveal that the enol form of the title compound is more stable than its keto form. The predicted non-linear optical properties of the title compound are much greater than ones of p-Nitroaniline. The changes of thermodynamic properties from the monomers to title compound with the temperature ranging from 200 K to 450 K have been obtained using the statistical thermodynamic method. At 298.15 K the change of Gibbs free energy for the formation reaction of the title compound is 30.654 kJ/mol. The title compound cannot be spontaneously produced from the isolated monomers at room temperature. The tautomeric equilibrium constant is computed as 0.0192 at 298.15 K for enol-imine ↔ keto-amine tautomerization of the title compound. In addition, natural bond orbital analysis of the title compound were performed using the B3LYP/6-31G(d) method.