Relaxations of methylpyridinone tautomers at the C60 surfaces: DFT studies

Abstract

Density functional theory (DFT) based calculations have been performed to examine the relaxations of tautomers of 4âhydroxyâ6âmethylpyridinâ2(1H)âone (MPO), as a representative of pyridinone derivatives, at the fullerene (C₆₀) surfaces. Optimized molecular properties including energies, dipole moments and atomic scale quadrupole coupling constants (C_Q) have been evaluated to investigate the structural and electronic properties of the models. The structural configurations of tautomers show different relaxations at the C₆₀ surface yielding different magnitudes of total and binding energies. Moreover, deformation of each tautomer due to relaxation at the C₆₀ surface with respect to the initial singular structure has been examined. Complimentary parameters of energy gaps and dipole moments exhibit the effects of relaxations at the C₆₀ surface for the MPO counterparts. Atomic scale C_Q properties also indicate that the electronic properties of atoms show significant changes for tautomers and hybrid systems. As a final note, the tautomeric structures in singular and hybrid forms exhibit different electronic properties because of effects of interactions with C₆₀, especially for the interaction regions.