Hybrid Orbitals
Part 2. sp2
Hybridization of Carbon
sp2 hybridization is best illustrated
using ethene, C2H4. The carbon atoms in
this molecule are sp2 hybridized.
- Note that each carbon now has only three bonds, and that
the bonds about each carbon atom are coplanar, with 120o
bond angles throughout. Note also that the C-C bond is a double
bond, i.e. 4 electrons.
-
- To make these bonds, the s orbital and two of the p
orbitals of carbon are hybridized to for three equivalent
sp2 hybrid orbitals. (Remember for now that
this leaves one p orbital of carbon un-used.) Each sp2
orbital looks like the following. Use
the mouse to rotate the figure.
-
- When the three sp2 hybrids are arranged around
the carbon nucleus, we have:
-
-
- To form the C-C bond, an sp2 hybrid from one
carbon atom overlaps with that of the other, creating a
C-C single bond. This type of bond, resulting from the
end-on interaction of the two hybrid orbitals, is termed
a "sigma" bond. The other four sp2
hybrids are used to make single bonds with the hydrogens.
Remember that left over p orbital on each carbon atom? These
two now overlap to produce another bond between the carbon atoms.
This "pi" bind and the C-C sigma bond constitute the
double bond between the carbons. Note the extra electron density
between the carbons.
Cool, eh?
Back to part 1,sp3
hybridization
On to part 3, sp
hybridization
Chicken
out