Over the last twenty years, several kinds of interesting carbon structures have been found: fullerenes and endohedral fullerenes, onions, carbon nanotubes and related structures, and other structures somewhat difficult to classify. Different conditions are required to form each of these structural motifs. The potentially most useful new materials are the fullerenes particularly C60 and single-walled carbon nanotubes. Considering the high temperature conditions required for their synthesis from condensing elemental carbon, amazingly high yields of fullerenes and single-walled carbon nanotubes have been achieved.

However, finding and verifying sound chemical mechanisms to account for the formation of these various structures presents a severe challenge to chemists. As an example, several mechanisms have been proposed for the formation of C60, but devising experimental tests that will distinguish among these mechanisms has proved difficult. Achieving precise control over the mix of products is even more challenging. This cornucopia of new elemental carbon structures ought to result in many new practical applications, but finding these applications is yet another major challenge to chemists and inventors. This talk will survey these new carbon structures and the issues just raised.