Engineering Chemistry S Datta

p y
p x
p z dz 2 dsp 3
24 ENGINEERING CHEMISTRY
corners of a square. So, the shape of the molecule becomes square planar and the bond angle is
90° (see Table 2.3).
dsp 3 or sp 3 d hybridization
In this type of hybridization d z
2 orbital and one s-orbital and three p-orbitals mix to give
five orbitals (Fig. 2.14). But in this case, the hybrid orbitals are not equivalent. The hybrid
orbitals consist of one group of two equivalent oppositely directed orbitals and the second group
of three equivalent orbitals. The shape of the molecule will be trigonal bipyramidal (Fig. 2.15).
s
Example of sp 3 d hybridization:
Electronic configuration of:
Fig. 2.14 sp 3 d hybridization.
P-atom in ground state
3s
3p
3d
P-atom in the excited state
Five unpaired
electrons
sp 3 d hybridization
3d
These sp 3 d hybrid orbitals of one P-atom overlap with five p orbitals of five Cl atoms to
form PCl 5
. The shape of the molecule is trigonal bipyramidal (Fig. 2.15).
Cl
Cl
P
Cl
Cl
Cl
Fig. 2.15 Trigonal bipyramidal structure of PCl 5
.