Strong Electronic Polarization of the C60 Fullerene by the Imidazolium-Based Ionic Liquids: Accurate Insights from Born-Oppenheimer Molecular Dynamics Simulations

TL;DR

This study uses advanced Born-Oppenheimer molecular dynamics simulations to reveal significant electronic polarization effects in C60 fullerenes when immersed in imidazolium-based ionic liquids, highlighting non-negligible charge redistribution.

Contribution

First application of HDFT BOMD to investigate electronic polarization and charge transfer in C60 fullerenes within ionic liquids at finite temperature.

Findings

C60 exhibits a positive effective charge in RTILs.

Electronic polarization is significant despite negligible charge transfer.

HDFT BOMD is effective for studying electronic effects in complex systems.

Abstract

Fullerenes are known to be polarizable due to the strained carbon-carbon bonds and high surface curvature. Electronic polarization of fullerenes is of steady practical importance, since it leads to non-additive interactions and, therefore, to unexpected phenomena. For the first time, hybrid density functional theory (HDFT) powered Born-Oppenheimer molecular dynamics (BOMD) simulations have been conducted to observe electronic polarization and charge transfer phenomena in the C60 fullerene at finite temperature (350 K). The non-additive phenomena are fostered by the three selected imidazolium-based room-temperature ionic liquids (RTILs). We conclude that although charge transfer appears nearly negligible in these systems, an electronic polarization is indeed significant leading to a systematically positive effective electrostatic charge on the C60 fullerene: +0.14e in [EMIM][Cl], +0.21e in [EMIM][NO3], +0.17e in [EMIM][PF6]. These results are, to certain extent, unexpected providing an inspiration to consider novel C60/RTILs systems. HDFT BOMD provides a powerful tool to investigate electronic effects in RTIL and fullerene containing nuclear-electronic systems.