Density functional computational studies on 2‐[(2,4‐Dimethylphenyl)iminomethyl]‐3,5‐dimethoxyphenol

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 2‐[(2,4‐dimethylphenyl)iminomethyl]‐3,5‐dimethoxyphenol ( I ). To investigate the tautomeric stability, optimization calculations at B3LYP/6‐31G(d) level were performed for the enol and keto forms of I . Calculated results reveal that the enol form of I is more stable than its keto form. The predicted nonlinear optical properties of I are much greater than ones of urea. The changes of thermodynamic properties for the formation of the title compound with the temperature ranging from 200 to 500 K have been obtained using the statistical thermodynamic method. At 298.15 K, the change of Gibbs free energy for the formation reaction of I is 32.973 kJ/mol. The title compound can not be spontaneously produced from the isolated monomers at room temperature. The tautomeric equilibrium constant is computed as 0.868 at 298.15 K for enol‐imine↔keto‐amine tautomerization of I . In addition, natural bond orbital analysis of I was performed using the B3LYP/6‐31G(d) method. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012