Credit: © 2006 RSC

The assembly of well-defined nanostructures from buckminsterfullerene (C60) building blocks is not straightforward. It often requires long sequences of chemical transformations and is further complicated by the purification procedures necessary along the way. Now, researchers in France have shown how small cages made from tin and oxygen atoms — known as stannoxanes — can be used to quickly and easily assemble fullerene-rich structures.

The faces of these small prismatic cages are known to bind carboxylic acids. In this way, six copies of a molecule that have such a group can be organized in a precise manner around a central core. Jean-François Nierengarten and co-workers1 from the Laboratoire de Chimie de Coordination du CNRS in Toulouse made compounds in which either one or two buckyballs were linked through a spacer to a single carboxylic acid group. When these compounds were heated in the presence of a small organic precursor containing both tin and oxygen atoms, pure multi-fullerene nanostructures were assembled with very high efficiency.

The central stannoxane cage was shown not to affect the electrochemical properties of the assembled fullerenes. Each buckyball behaved independently, just like the parent fullerene compounds. Consequently, Nierengarten suggests that such fullerene-rich structures, could be potentially useful materials for solar cells.