Planes and Reflection (σ)

• σ_h(horizontal): plane perpendicular to principal axis
• σ_d(dihedral), σ_v(vertical): plane olinear with principal axis
  • σ_d: σ parallel to C_n and bisecting two C₂' axes
  • σ_v: Vertical, parallel to principal axis

Examples:
Eye Glasses	Hands	Chair
Look at a pair of glasses and see the reflection symmetry from the center. There is no other symmetry.	Look at your hands to see reflection symmetry. Can you see any more symmetry operations?
Back to top H20
Click to see in details
Mirror planes must either bisect the molecule or contain all atoms in a molecules. The mirror planes for H20are examples of each of these situations.
Back to top CO2
Infinite planes
Is it hard to see infinite number of reflection planes? All of those planes contain all three atoms.
Back to top Benzene
How many planes can you see?
If you said 7 for the above question, you are on the right track. Guess which one is the seventh. For hint, check the water example above. Back to top