Pi bonds
- Formed from parallel overlap of adjacent p orbitals
- Do not form single bonds
- Located above and below the plane of the molecule
- Side-by-side overlap of p orbitals (weaker than head-on overlap)
Bonds - 2. Pi Bonds: Visualization
Pi Bonds
- Pi bonds are bonding molecular orbitals formed from parallel overlap of adjacent p orbitals.
- Pi bonds do NOT form single bonds.
- A single pi bond is found above and below the plane of the molecule.
- The overlap of pi bonding is weaker than the head-on overlap of sigma bonding.
Next let's visualize a pi bond, which span above and below the plane of the molecule.
- Draw the Lewis structure for ethylene: its double bond contains a Pi bond.
First visualization
- Draw our carbon-carbon bond.
- Then, draw the carbon-hydrogen bonds.
- Now, draw a sigma bond along the carbon-carbon bond axis.
- Then draw the two halves of a Pi bond above and below the sigma bond.
Second visualization
- Draw two sp2 orbitals connected.
- Then in perpendicular to them, draw p orbitals.
- Connect the p orbitals with the Pi bond above and below the plane of the molecule.
For completeness, write that:
- Single bonds comprise 1 sigma bond
- Double bonds comprise 1 sigma bond & 1 pi bond
And what about triple bonds?
- Triple bonds comprise 1 sigma bond & 2 pi bonds