Hybridization ofAtomic Orbitals

PGCC CHM 101 Sinex

Illustrating hybridization

Shockwave animation of hybridizationclick here

Chime site with atomic and hybrid orbitals

click here

Now let’s make some bonds!

hybrid orbitals – sp, sp2, or sp3

formation of bond

remaining p orbitals from sp or sp2

bond

formation of bond

Planar molecule (each carbon is trigonal planar) with cloud above and below the plane

bond hinders rotation about the carbon-to-carbon bond

Bond formation from hybridization

• Single bond - sigma bond

• Double bond – sigma bond + pi bond

• Triple bond – sigma bond + pi bond + pi

bond How are the two pi bonds in the triple bond oriented?

end-to-end

side-to-side

How about the electron density around a carbon-carbon bond?

C2H6

C2H4C2H2

single bond double bond triple bond Spartan 02

Polar orNon-polar

H+

attack?

1

2

3

45

6

7

What is the hybridization in each carbon atom?

sp3 – 2, 5tetrahedral

sp2 – 1, 3, 4trigonal planar

sp – 6, 7linear

What is the hybridization in each carbon atom?

1

2

3

4

Draw the Lewis dot structure – C3H4

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:C:C:::C:H

H

H

..

..C::C::C

H

H

..

..

H

H

..

..

Build the molecular model.

Allene, H2C=C=CH2

The 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.

What is the hybridization?

Spartan 02