Carbon allotropes

The physical properties depend on the chemical bonding

Diamond Strong covalent bonds in 3 dimensions Every carbon atom bonds 4 other carbon atoms in a crystalline lattice The hardest material known

Diamond Hard, colourless, insulator Tetrahedral, giant structure Covalent bond => sp 3 orbitals (HL)

Graphite Animation The double bonds are delocalised and move- electric conductivity in the plane The planes bond with weak intermolecular bonds- van der Waals bonds The layers move easily- graphite colours

Graphite Slippery, black, electricity conductor Layers of fused six-membered rings. Each carbon surrounded by three others in a planar trigonal arrangement => sp 2 + p-orbital (HL) The p-orbital is perpendicular to the layer and give close packed p-orbitals stabilise the layers Delocalisation of electrons => electrical conductivity

Fullerenes och nanotubes Nanotubes

Fullerene, C 60 Spherical molecule. Looks like a football. 12 pentagons and 20 hexagons. Bonds: C 60 –hydration  C 60 H 60 (C 2 H 4 + H 2  C 2 H 6 ; 1 H 2 / double bond) Each carbon has a double bond

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