Buckminsterfullerene

C60 was founded in 1985 by Robert Curl, Harold Kroto, and Richard Smalley.  In 1990, W. Kretschmer described the first actual synthesis of  C60, a molecule shaped like a football and called Buckminsterfullerene. The experiment of Kroto involves a technique that uses a laser to vaporise a graphite rod in a helium stratosphere to produce carbon plasmas; graphite is the precursor of C 60 . Buckminsterfullerene is the most common naturally occurring fullerene and is found in deep black powdery substances consisting mainly of amorphous carbon. Buckminsterfullerene contains twenty-six-membered rings and twelve five-membered rings. The bonds shared by a five-membered and a six-membered ring are 1.45 Å long. Buckminsterfullerene’s importance is seen in medical science, nanotechnology, lubricants and as a catalyst. The C60 molecule might be called the world’s smallest soccer ball.

Structure of Buckminsterfullerene

Buckminsterfullerene is a curtail icosahedron with 60 vertices and a carbon atom at the vertices of each polygon and 32 faces of which, 20 are hexagons and 12 are polygons and have a bond along all the polygon edges. The outer diameter of the C60 molecule is 7.10 Å, all the carbon atoms are identical and they undergo sp2 hybridisation each carbon atoms form three Sigma bonds with three other carbon atoms. The unused electron at each carbon is delocalised in molecular orbitals, which in turn give a scented character to the molecule.  The C60 ions are orientationally disarranged in the lattice. Buckminsterfullerene crystallises into a face-centred cubic lattice with large octahedral and smaller tetrahedral holes. The closed fullerenes, especially C60, are also casually called buckyballs. Buckyball is a nanoparticle characterised by a spherical geometry and is hollow from inside comprising 60 carbon atoms. 

Properties of Buckminsterfullerene 

Buckminsterfullerene was the biggest known molecule noted to exhibit wave-particle duality. It is a solid, usually black, that dissolves and becomes a solution in organic solvents like benzene, toluene, etc. to produce a violet solution. It is nearly insoluble in water. C60  solid is as soft as graphite, but when compressed to less than 70 percent of its volume, it gets converted into a harder form of the diamond. Buckminsterfullerene has an average diameter of 0.7 nm, and an average density of 1.72 g/cm3. Heat of hydrogenation of  buckminsterfullerene is 38.1 kJ/mole.

Buckminsterfullerene has a molar mass of 720.64 g/mole; its melting and boiling points are approximately 553 k and 800 k, respectively. The molecule can withstand high temperatures and high pressures; its thermal conductivity is 0.4 W/mK (300 K), and its electrical resistivity is 1014 Ohms/m.

The Chemical Reaction of Buckminsterfullerene

• Hydrogenation

C60 shows a small amount of aromatic character and an addition reaction with hydrogen to give poly hydro fullerenes. It reacts with lithium in the presence of liquefied ammonia, accompanied by three-degree butanol to give a composition of poly hydro fullerenes.

• Cycloaddition 

The C60 molecules can undergo cycloaddition reaction giving the dumbbell-structured compound C120. The coupling is attained by a rapidly 

vibrating mill in the presence of KCN, which behaves as a catalyst. The reaction is alterable as C120 disintegrates back into two molecules of C60 when heated at 450 K. Repeated cycloaddition between C60  at high temperature and pressure results in the formation of polymerised fullerene.

• Halogenation 

Buckminsterfullerene shows an additional reaction with halogen. Its structure is changed into a drum-shaped molecule after reacting with fluorine and chlorine.

• Reaction with oxygen atoms

Solutions of buckminsterfullerene react with oxygen atoms to form the epoxide  C60O. Buckminsterfullerene reacts with ozone in the presence of 1,2-dimethylbenzene (o- xylene) at -16 degrees Celsius to give an intermediate product which is analogous to ozone also called ozonide. C60O3 can be decomposed into two forms of C60O. Decomposition of C60O3 at 23 degrees Celsius gives the epoxide; however, decomposition or separation of molecules in the presence of light gives a product in which the O atom is present at bridge head position.

Importance of Buckminsterfullerene

Buckminsterfullerene importance is seen in the pharmaceutical industry as :-

1. Buckminsterfullerene acts as an antioxidant and helps to reduce damage due to oxygen.
2. It acts as an antiviral agent and helps fight against viruses that can cause diseases.
3. It is used in gene and drug delivery systems.
4. It acts as an essential drug in photodynamic therapy.
5. Its importance is also seen in radiculopathy treatment (a disease of the nerve’s root).

Buckminsterfullerene importance and applications based on its redox properties :-

1. It is used in deterioration treatment.
2. It is also used in osteopenia therapy and helps fight multiple sclerosis. 

Conclusion 

Buckminsterfullerene is the most common naturally occurring fullerene. It is the third allotrope of carbon and is found in deep black powdery substances consisting mainly of amorphous carbon. Buckminsterfullerene contains twenty-six-membered rings and twelve-five membered rings. It is shaped like a soccer ball and is also called buckyballs. C60 shows a minor aromatic character and dissolves in organic solvents like benzene and toluene, and it is insoluble in water. Buckminsterfullerene is usually an insulator, but they behave as semiconductors when doped with alkali metals. Buckminsterfullerene’s importance and application are seen in many industries as antioxidants, cosmetics, antiviral agents, and drug delivery systems.