Si60, an Analogue of C60?

Bearing in mind the further miniaturization in microelectronics and the possibility of discovering new materials, as was the case with the fullerenes, many research groups are at present studying clusters of semiconductor elements like silicon. Reactions of mass-selected Sin clusters with reactive gases such as ethylene and subsequent analysis of the products provide information on the structures of these complexes. Thus for instance, Si10 does not have the adamantane structure expected from the structure of elemental silicon, but a compact structure (two calculated structures of almost the same energy are depicted for Si10) with fewer free valencies at the Si atoms. There is no evidence for a “round Si60 chemistry” analogous to that of C60, although Si60 represents a stability maximum (calculated structure depicted to the right). A direct structure determination will probably remain elusive for some time, because the absolute stability of Si60 is orders of magnitude smaller than that of C60.