Structure of Fullerene
The icosahedral C60H60 cage was mentioned in 1965 as a possible topological structure. Eiji Osawa of Technology predicted the existence of C60 in 1970. He noticed that the structure of a corannulene molecule was a subset of an Association football shape, and he hypothesized that a full ball shape could also exist. Japanese scientific journals reported his idea, but neither it nor any translations of it reached Europe or the Americas.
Also in 1970, R. W. Henson (then of the Atomic Energy Research Establishment) proposed the structure and made a model of C60. Unfortunately, the evidence for this new form of carbon was very weak and was not accepted, even by his colleagues. The results were never published but were acknowledged in Carbon in 1999.
In 1973, independently from Henson, a group of scientists from the USSR made a quantum-chemical analysis of the stability of C60 and calculated its electronic structure. A fullerene is a molecule of carbon in the form of a hollow sphere, ellipsoid, tube, and many other shapes. Spherical fullerenes, also referred to as Buckminsterfullerene’s resemble the balls used in association football. Cylindrical fullerenes are also called carbon nanotubes (buckytubes). Fullerenes are similar in structure to graphite, which is composed of stacked graphene sheets of linked hexagonal rings. Unless they are cylindrical, they must also contain pentagonal (or sometimes heptagonal) rings.
The first fullerene molecule to be discovered, and the family’s namesake, buckminsterfullerene (C60), was manufactured in 1985 by Richard Smalley, Robert Curl, James Heath, Sean O’Brien, and Harold Kroto at Rice University. The structure was also identified some five years earlier by Sumio Iijima, from an electron microscope image, where it formed the core of a “bucky onion”. Fullerenes have since been found to occur in nature. More recently, fullerenes have been detected in outer space. According to astronomer Letizia Stanghellini, “It’s possible that buckyballs from outer space provided seeds for life on Earth.
The discovery of fullerenes greatly expanded the number of known carbon allotropes, which had previously been limited to graphite, graphene, diamond, and amorphous carbon such as soot and charcoal. Buckyballs and buckytubes have been the subject of intense research, both for their chemistry and for their technological applications, especially in materials science, electronics, and nanotechnology.
By – Assistant Professor – Mr. Ranjeet Kumar Jha
Uttaranchal (P.G.) College Of Bio-Medical Sciences & Hospital