Dihedral Angles:

Dihedral angles are a measure of the rotation about a bond.

• For four atoms A-B-C-D, the dihedral angle measures the rotation about the B-C bond.
• It is the angle formed between two planes, the plane defined by A-B-C (yellow) and the plane defined by B-C-D (green).
• A positive dihedral angle is a clockwise rotation of the first plane on to the second.
• A negative dihedral angle is a counterclockwise rotation.

Use the following check boxes to add the planes (select only ONE angle at a time):

Hint: Rotate the molecule such that atoms B and C are on top of each other, i.e. you are looking down the B-C bond. Rotate the molecule a little, so that you can see the relative angle between the two planes.

You may find it useful to remove the hydrogens to reduce the clutter:

Color Scheme:
 blue - nitrogen
 red - oxygen
 gray - carbon
 yellow - sulfur
 hydrogen - white

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