sp hybridization

The final example of hybridization we will examine is the molecule ethyne (C₂H₂) (Figure 1.1 Ethyne).

Figure 1.1. Ethyne.

The carbons in ethyne are each sigma bonded to a single hydrogen, but triple bonded to each other. Again, the models of hybridization we have looked at so far are insufficient to explain the bonding pattern observed. In ethyne, only the 2s and one of the 2p orbitals hybridize to give two new sp hybridized orbitals capable of forming the two σ bonds of each carbon in ethyne (Figure 1.2 Hybridization of carbon to generate sp orbitals).

Figure 1.2. Hybridization of carbon to generate sp orbitals.

The two hybridized sp orbitals arrange linearly with a bond angle of 180 ^o following VSEPR (Figure 1.3 A carbon atom linear sp hybridized orbitals ).

Figure 1.3. A carbon atoms linear sp hybridized orbitals.

The two remaining unhybridized 2p orbitals in both carbons are left available to form the triple bonds two π bonds.