Mixed Dimetallic Cluster Fullerenes: ScGdO@ C3v(8)-C82 and ScGdC2@ C2v(9)-C82.

Abstract

Mixed-metal cluster fullerenes have been extensively studied in recent years for their rich structural variability of the encaged clusters and have shown great potential in applied studies such as biomedicine and molecular electronic devices. However, the studies in this field have mostly concentrated on the nitride cluster fullerene, and very few other types of mixed-metal cluster fullerenes have been reported so far. Herein, we report the synthesis and isolation of the first mixed-metal oxide cluster fullerene, ScGdO@C82, and a novel mixed dimetallic carbide cluster fullerene, ScGdC2@C82. Spectroscopic and electrochemical studies combined with density functional theory (DFT) calculations assigned the molecular structure of the two cluster fullerenes (CFs) to ScGdO@ C3v(8)-C82 and ScGdC2@ C2v(9)-C82, respectively. DFT calculations also suggested that these two mixed-metal clusters are likely to be found in any of the three isolated pentagon rule Cs(6)-C82, C3v(8)-C82 and/or C2v(9)-C82 cages. The electrochemical studies show that the electrochemical gap of ScGdO@ C3v(8)-C82 and ScGdC2@ C2v(9)-C82 are 1.49 and 1.08 V. Moreover, comparative studies of ScGdO@ C3v(8)-C82 and Sc2O@ C3v(8)-C82, ScGdC2@ C2v(9)-C82 and Sc2C2@ C2v(9)-C82 showed that, despite their close structural resemblance, the replacement of one Sc ion by a Gd ion resulted in notable changes in their electrochemical behaviors as well as their 45Sc NMR spectra.