Relaxations of methylpyridinone tautomers at the C60 surfaces: DFT studies

Density functional theory (DFT) based calculations have been performed to examine the relaxations of tautomers of 4–hydroxy–6–methylpyridin–2(1H)–one (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 (CQ) 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 CQ 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.