Which of the following molecules has/have a cage-like structure?

I. Diamond

II. Graphite

III. Fullerene

The correct answer is Fullerene

Key Points

• Fullerene has a cage-like structure.
• Fullerene is an allotrope of carbon that has a unique structure consisting of hexagonal and pentagonal rings that attach to itself and form a cage-like structure or soccer-like structure.
• The first example of fullerene is Buckminsterfullerene (C60). This allotrope of carbon is named fullerene after the architect Richard Buckminster Fuller because the structure of C60 resembles the structure of the geodesic dome he designed.
• Harold Kroto, Robert Curl and Richard Smalley were given the Nobel Prize in chemistry in 1996, for the discovery of this carbon allotrope, fullerene C60.

Additional InformationDiamond

• Diamond is the purest crystalline allotrope of carbon having several carbons, linked together tetrahedrally.
• Each carbon atom in a diamond is surrounded by four other carbon atoms and connected to them by strong covalent bonds - the strongest type of chemical bond. 
• Colourless diamonds are used in making gems and colored diamonds like black diamonds are used in glass cutting and in making rock drilling machines.
• Carbon having Atomic Number 6 and mass Number 12 occurs in nature abundantly in both free and compound forms.
• The other Allotropes of Carbon are Graphite, fullerenes, Lonsdaleite, Graphene, and Linear acetylenic carbon (Carbyne).
• The allotropes of carbon like diamond, graphite coal, etc are crystalline solids but wood, stone are non-crystalline solids.

Graphite

• Graphite is an allotrope of carbon.
• It is a conductor of heat and electricity.
• It has a lower density than diamond.
• Graphite is used as a lubricant in high temperatures.
• Because it has a high melting point.