Hybridization
Why Hybrid Orbitals?
•
Some bonding schemes require more than
simple sigma and pi bonding of pure atomic
orbitals.
•
Hybrid orbitals are formed by combining
pure atomic orbitals to create highly
directional orbitals.
•
The five types of commonly found hybrid
orbitals are: sp, sp2, sp3, dsp3 (or sp3d), and
d2sp3 (or sp3d2).
sp Hybrid Orbitals
•
One s and one p with the same principal
quantum number are combined to form two
sp hybrid orbitals.
•
The sp orbitals lie in a straight line, separated
by 180 degrees.
•
The remaining p orbitals are unchanged.
sp Hybrid Orbitals
•
Consider sp hybridization in carbon atom:
2p
2s
Before
After
sp Hybrid Orbitals
•
Consider sp hybridization in carbon atom:
2p
2p
2s
Before
After
sp Hybrid Orbitals
•
Consider sp hybridization in carbon atom:
2p
2p
2s
Before
After
sp Hybrid Orbitals
•
Consider sp hybridization in carbon atom:
2p
2p
2s
Before
After
sp Hybrid Orbitals
•
Consider sp hybridization in carbon atom:
2p
2p
sp hybrid
2s
Before
After
2
sp Hybrid
Orbitals
•
One s and two p with the same principal
quantum number are combined to form
three sp2 hybrid orbitals.
•
The sp2 orbitals lie in a plane, separated by
120 degrees, pointing to the corners of an
equilateral triangle.
•
The remaining p orbital is unchanged.
2
sp
•
Hybrid Orbitals
Consider sp2 hybridization in silicon atom:
3p
3s
Before
After
2
sp
•
Hybrid Orbitals
Consider sp2 hybridization in silicon atom:
3p
3p
3s
Before
After
2
sp
•
Hybrid Orbitals
Consider sp2 hybridization in silicon atom:
3p
3p
3s
Before
After
2
sp
•
Hybrid Orbitals
Consider sp2 hybridization in silicon atom:
3p
3p
3s
Before
After
2
sp
•
Hybrid Orbitals
Consider sp2 hybridization in silicon atom:
3p
3p
sp2 hybrid
3s
Before
After
3
sp Hybrid
Orbitals
•
One s and three p with the same principal
quantum number are combined to form four
sp3 hybrid orbitals.
•
The sp3 orbitals are separated by 109
degrees, pointing to the corners of a
tetrahedron.
•
There are no remaining p orbitals.
3
sp
•
Hybrid Orbitals
Consider sp3 hybridization in nitrogen atom:
2p
sp3 hybrid
2s
Before
After
3
sp
•
Hybrid Orbitals
Consider sp3 hybridization in nitrogen atom:
2p
sp3 hybrid
2s
Before
After
dsp3/sp3d Hybrid
Orbitals
•
One s, three p, and one d with the same
principal quantum number are combined to
form five dsp3/sp3d hybrid orbitals.
•
Three dsp3/sp3d orbitals are separated by 120
degrees, pointing to the corners of an
equilateral triangle, in one plane.
•
The two remaining orbitals are 180 degrees
to each other, and 90 degrees from the first
three. This shape is a trigonal bipyramid.
•
The remaining d orbitals are unchanged.
3
dsp
•
Hybrid Orbitals
Consider dsp3 hybridization in sulfur atom:
3d
3d
3p
dsp3 hybrid
3s
Before
After
3
dsp
•
Hybrid Orbitals
Consider dsp3 hybridization in sulfur atom:
3d
3d
3p
dsp3 hybrid
3s
Before
After
d2sp3/sp3d2 Hybrid
Orbitals
•
One s, three p, and two d with the same
principal quantum number are combined to
form six d2sp3/sp3d2 hybrid orbitals.
•
The d2sp3/sp3d2 orbitals point in the six
directions of the Cartesian axes; they are all
90 degrees apart. This shape is an
octahedron, or square bipyramid.
•
The remaining d orbitals are unchanged.
2
3
d sp
•
Hybrid Orbitals
Consider d2sp3 hybridization in sulfur atom:
3d
3d
3p
d2sp3 hybrid
3s
Before
After
2
3
d sp
•
Hybrid Orbitals
Consider d2sp3 hybridization in sulfur atom:
3d
3d
3p
d2sp3 hybrid
3s
Before
After