CHM 101
Sinex
Illustrating hybridization
Hybridization of
Atomic Orbitals
Shockwave animation of hybridization
click here
Chime site with atomic and hybrid orbitals
click here
PGCC CHM 101 Sinex
Now let’s make some bonds!
hybrid orbitals – sp, sp2, or sp3
formation of σ bond
1
CHM 101
Sinex
σ bond
remaining p orbitals from sp or sp2
π bond hinders rotation
about the carbon-tocarbon bond
Planar molecule (each carbon
is trigonal planar) with π cloud
above and below the plane
formation of π bond
Bond formation from
hybridization
• Single bond
end-to-end
- sigma bond
side-to-side
• Double bond
– sigma bond + pi bond
• Triple bond
– sigma bond + pi bond + pi bond
How about the electron density
around a carbon-carbon bond?
Polar or
Non-polar
C2H6
C2H4
C2H2
H+
attack?
How are the two pi bonds in the triple bond oriented?
single bond
double bond
triple bond
Spartan 02
2
CHM 101
Sinex
What is the hybridization in each carbon atom?
4
2
5
What is the hybridization in each carbon atom?
4
6
3
3
7
1
2
1
sp3 – 2, 5
tetrahedral
sp2 – 1, 3, 4
trigonal planar
sp – 6, 7
linear
Draw the Lewis dot structure –
C3H4
Allene, H2C=C=CH2
What is the hybridization?
Remember to chain the carbon atoms and fill
the octet of the center carbon atom in the
chain first.
You should have come up with one of these structures:
H
..
H:C:C:::C:H
..
H
H
H
..
..
C::C::C
..
..
H
H
Build the molecular model.
The π clouds of the two double bonds are oriented
perpendicular to each other. Hence the hydrogens
are turned 90o. The is due to the original orientation
of the p orbitals on the center carbon atom.
Spartan 02
3