Effect of Methylation on 2-Hydroxypyridine in Ground State: Theoretical Study

A systematic study on the methyl substituted 2-hydroxypyridine molecule is presented in this paper to investigate the methylation effect in the ground electronic state (S0) using ab initio calculations. The minimum energy conformation of these molecules was evaluated using Hartree-Fock (HF), second order Mollar Plesset perturbation (MP2) and B3LYP density functional level of theories and TZVP Gaussian type basis set. B3LYP/TZVP level of theory was used for the natural bond orbital (NBO) calculations to get insight into the substitution energy of the stationary states and also to estimate the role of Lewis and non-Lewis (delocalization) energies. The present study reveals that stabilization of these molecules is due to the change in nuclear-electron interaction energy. However, the local interactions to methyl group are the responsible term for the delocalization energy contribution.