Carbon is a uniquely useful element as it can form a variety of structural motifs such as zero- to three-dimensional architectures. Polycarbon species are abundant in nature, for example simple graphite, and depending on their electronic structures these compounds exhibit fascinating properties.

Thus carbido clusters are intriguing compounds which were originally studied as they formed key intermediates in catalysis. This research led to the discovery of polyynediyl complexes which are essentially linear carbon cluster  compounds. The pi-conjugated elements of these species can interact with metal fragments resulting in a variety of interesting chemical properties.  These compounds are currently being tested for use as molecular wires in miniaturised circuits. 

In their Dalton Transactions Perspective, Munetaka Akita and Takashi Koike, from the Tokyo Institute of Technology, Japan, discuss how carbon cluster chemistry has been extended to the promising study of molecular wires and switches.

'Molecular electronics are still in their infancy,' says Akita, but 'polycarbon cluster systems have been regarded as the most efficient molecular wires.'