http://www.ck12.org Chapter 9. Covalent Bonding
FIGURE 9.25
The process of sp^2 hybridization involves the mixing of one s orbital with a set of two p orbitals (pxand py) to form
a set of three sp 2 hybrid orbitals. Each large lobe of the hybrid orbitals points to one corner of a triangle.The occupied orbitals are then hybridized, and the result is a pair of sp hybrid orbitals. The two remaining p orbitals
(arbitrarily chosen to be pyand pz) do not hybridize and remain unoccupied.
The geometry of the sp hybrid orbitals is linear, with the large lobes of the two orbitals pointing in opposite directions
along one axis, arbitrarily defined as the x-axis (Figure9.26). Each can bond with a 1s orbital from a hydrogen
atom to form the linear BeH 2 molecule.
Other molecules whose electron domain geometry is linear and for whom hybridization is necessary also form sp
hybrid orbitals. Examples include CO 2 and C 2 H 2 , which will be discussed further in the next section on hybridization
and multiple bonds.
It should be noted that molecules with trigonal bipyramidal or octahedral electron geometries form different types
of hybrids that also involve the participation of one or more d orbitals. However, we will not consider these types of
hybrid orbitals here.