B. The Symmetry Properties of Metal Tris Chelates
2. With Asymmetrical Chelating Ligands: Molecules of C3 Symmetry
a. The C3 Operations


Example with one isomer of the Co(O-CH2CH2NH2)3 Molecule More Information
Unlike in our last example, this molecule contains three ligands that are asymmetrical (rather than three symmetrical ligands) and therefore will have lower symmetry.
This molecule has C3 symmetry and ONLY the following THREE symmetry operations:
E, C3 and C32
Because we have asymmetrical ligands, we no longer have the three C2 operations
Spin for a better look! (or use your mouse)
Below we show the C3 Operations
Useful commands for viewing the operations:
OR


Animation of the C3 Operations:
1. The C3
2. The C32
3. The The C33 = E
Notice the C33 is the same as the identity (E) and is therefore not unique and is therefore NOT listed as a symmetry operation for this molecule.

Finally, to show that this molecule DOES NOT have a C2 axis:

Notice that this 180o rotation interchanges the red (oxygen) and blue (nitrogen) atoms; therefore C2 is NOT a symmetry operation for this molecule.
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Resources developed by Marion E. Cass, Carleton College and updated in 2014. Computations and content done in consultation with Henry S. Rzepa, Imperial College, London