Infrared Spectroscopy of Symmetric and Spherical Top Molecules for Space Observation, Volume 2

5Fullerene Nanocage

Up until 1985, only two crystal phases of carbon were known, namely diamond and graphite. However, between 1960–1970, research conducted by theoretical scientists Osawa and Yoshida [OSA 70, YOS 71] led to the prediction of the existence of a stable molecule exclusively composed of carbon atoms, namely fullerene C₆₀.

The regular icosahedral structure of the fullerene C₆₀ molecule was discovered experimentally as result of the cooperation between astrophysicists and spectroscopists.

In 1985, Harold Kroto attempted to identify the unusual infrared (IR) spectrum emitted by large aggregates composed of carbon, known to be generated by red giant stars. In order to explain these spectra, he advanced the hypothesis according to which hydrocarbon molecules were present in the interstellar space.

At the same time, Richard Smalley’s group developed a laser vaporization technique for the synthesis of various species of aggregates, but more specifically of carbon aggregates. Their works suggested the possibility of creating unusual carbon molecules or aggregates.

Kroto and Smalley started their collaboration in view of the synthesis of hydrocarbon molecules from graphite and the study of their IR spectrum. They were surprised to notice the systematic presence of a molecule that could correspond to 60 carbon atoms. The systematic presence and the abundance of this molecule were indicators of its high stability.

After considerable effort, they formulated the hypothesis ...