Scientists in Japan have synthesised and characterised Ce₂@C₇₈ and its bis-silylated derivative. 

Endohedral metallofullerenes have received much attention owing to their fascinating structures, properties and chemical reactivities. Now, considerable interest has been directed toward dimetallofullerenes. Until now the dynamic behaviour of the metal atoms in other dimetallofullerenes has not been investigated. 

Takeshi Akasaka from the University of Tsukuba and Shigeru Nagase from the Institute for Molecular Science and colleagues have succeeded in synthesising Ce₂@C₇₈ and found its unique structure, property, and chemical reactivity. In addition, the bis-silylated derivative has also been investigated by means of spectroscopic and single-crystal X-ray structure analyses.    

'We have shed light on a new dimetallofullerene, Ce₂@C₇₈, and its bis-silylated derivative for the first time.' said Akasaka.   

The bis-silylated derivative in the crystal displays a chain of fullerene molecules along the a-axis. Such a one-dimensional nanostructure with well controlled composition and crystallinity may become the focus of intensive research on technological applications due to its dimensional anisotropy, says Akasaka. 

The researchers hope that the bis-silylation will also be applicable to various endohedral metallofullerenes such as Gd₂@C₇₈ to create novel MRI contrast reagents.