A
carbon–carbon bond is a
covalent bond between two
carbon atoms. The most common form is the
single bond: a bond composed of two
electrons, one from each of the two atoms. The carbon–carbon single bond is a
sigma bond and is formed between one
hybridized orbital from each of the carbon atoms. In
ethane, the orbitals are sp
3 hybridized orbitals, but single bonds formed between carbon atoms with other hybridisations do occur (e.g. sp
2 to sp
2). In fact, the carbon atoms in the single bond need not be of the same hybridisation. Carbon atoms can also form
double bonds in compounds called
alkenes or
triple bonds in compounds called
alkynes. A double bond is formed with an sp
2 hybridized orbital and a p-orbital that isn't involved in the hybridization. A triple bond is formed with an sp
hybridized orbital and two p-orbitals from each atom. The use of the p-orbitals forms a
pi bond.