Unexpected diverseness on electronic density and bonding behaviours for Sc2X@C2v(63751)-C86 and Sc2X@C1(63755)-C86 (X = S and O)

Abstract

Decisive investigations on stabilities of Sc2O@C86 and Sc2S@C86 isomers were carried out via density functional theory with statistical thermodynamic method. Sc2X@C2v(63751)-C86 and Sc2X@C1(63755)-C86 (X = O and S), observing isolated pentagon rules, were confirmed as thermodynamically preferred isomers within fullerene-formation temperature. Particularly, it is the first time to acknowledge C1(63755)-C86 as host for encapsulating Sc2X (X = O and S), herein. Interactions between Sc and non-metal atoms in Sc2X@C2v(63751)-C86 and Sc2X@C1(63755)-C86 (X = O and S) were specifically explored. Importantly, characteristics and electron density ellipticity for independent X-Sc (X = O and S) bonds and their bonding paths performed clear distinction due to weak intramolecular interaction.