Home > Community > Why are Newman Projections drawn with 120 degrees when actually sp3 carbons are 109.5 degrees?
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Marko Sokolich

Why are Newman Projections drawn with 120 degrees when actually sp3 carbons are 109.5 degrees?

Bob Mathews  Follow

It is a projection. Depending on the orientation of a water molecule with respect to the projection plane, the projected angle can be anywhere from zero to 180 degrees. Similarly, the angles in ethane projected to a 2D plane will be different from 109.5 degrees unless the three atoms making up the angle are in the plane:

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Other projections (Fisher projection) make the angles appear as right angles. In either case, the 3D angles remain at 109.5 degrees.

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