BUCKYBALL AND ITS DISCOVERY

What are Buckyballs?

 Buckyballs(short for Buckminster fullerenes) are spherical structures of carbon where each carbon atom is bonded to three other carbon atoms. The carbon atoms are not only arranged in hexagons but are also arranged in pentagons. These pentagons allow the sheet of carbon to curve into a sphere.

 The fullerene family of molecules is often identified by the letter C followed by the number of carbon atoms, for example,C60, C70, C80. The C60 variant, having 60 carbon atoms arranged in a sphere, comprises 20 hexagons and 12 pentagons.  This type of spherical carbon molecule has been found in various other sizes. Buckyballs are also considered as an allotrope of carbon other than graphite and diamond.

Discovery

Sir Harold Kroto, Richard Smalley and Bob Curl 
receiving the Nobel Prize

This unique material was discovered as a result of collaboration between researchers from different universities during a joint research project in 1985. The researchers involved in this serendipitous discovery were Richard Smalley and Bob Curl of Rice University and Sir Harold Kroto of the University of Sussex. They also received their Nobel Prize in 1996 for this discovery.

Sir Harold Kroto and his students were studying the catenation properties of carbon and nitrogen molecules. Meanwhile, at the same time, astrophysicists were working with spectroscopists to understand the infrared emissions from a giant red carbon star. A carbon star is basically a star whose atmosphere contains more percentage of carbon than oxygen. Kroto recognized that the spectroscopic signatures of the compounds found near the carbon star resembled the molecules he has been creating in his laboratory. Since creating a carbon star was not possible, the next best option was to use the laser vaporization technique available with Richard Smalley of Rice University.

A laser beam was directed towards a solid rotating graphite disc resulting in the formation of carbon vapors. These vapors were then passed through a stream of high-density helium gas and were subsequently cooled and ionized to form carbon clusters.

On further scrutiny of the formed carbon clusters, they found an unknown molecule containing 60 carbons among a myriad of other molecules formed. It was also observed that these were the only molecules formed when the laser vaporization process was further optimized. After many discussions, inspection, and modeling, they finally concluded about the molecule's structure. Its resemblance to the American architect Buckminster Fuller's geodesic dome gave it the name Buckminster fullerenes.

An example of a geodesic dome