Fullerene C60 spectroscopy in [BMIM][PF6] ionic liquid: Molecular dynamics study using polarization effects

Abstract

We employ molecular dynamics (MD) simulations to assess the electrical behavior of the atomic charges of a fullerene immersed in an ionic liquid (and water). From solute-solvent configurations and DFT calculations, we obtained the atomic charges and the dipole moment in each stage of MD-simulation. Through an iterative process alternating MD-simulations and DFT calculations we obtained the convergence of the C60 dipole moment in solution. A complete analysis of the behavior of atomic charges is presented comparing the impact on the solute-solvent structure, where we highlight the importance of the complete polarization of the solute in solution. To observe the impact of electronic C60-solvente interaction on spectroscopy results we performed nuclear magnetic resonance (NMR) and absorption spectra quantum calculations, using GIAO-DFT and TD-DFT methodology. The results indicate a smaller chemical shift, δ(13C) and a more intense electronic transition band for the fully polarized C60 in solution.