Diethyl malonate adds to these compounds in the presence of a base in the Bingel reaction, and pure solutions of them exhibit a deep purple color.  Complexes of them with helium have been found in meteorites, and when complexed with alkali or alkali earth metals, they displa
Diethyl malonate adds to these compounds in the presence of a base in the Bingel reaction, and pure solutions of them exhibit a deep purple color.  Complexes of them with helium have been found in meteorites, and when complexed with alkali or alkali earth metals, they display superconductivity at relatively high temperatures.  All of their atoms are sp2 hybridized, though one bond angle is strained to 108 degrees.  Discovered when Kroto, Smalley, and Curl used a high power laser to vaporize an allotrope of them, nanotubes are essentially stretched versions of them.  FTP name these compounds, the first example of which was C60, named for the creator of the shape they resemble, geodesic domes.
Diethyl malonate adds to these compounds in the presence of a base in the Bingel reaction, and pure solutions of them exhibit a deep purple color.  
buckminsterfullerenes [or 'bucky balls']