What is the difference between axial and equatorial positions?
The key difference between axial and equatorial position is that axial bonds are vertical while equatorial bonds are horizontal. A conformation is a shape a molecule can take due to the rotation around one or more of its bonds.
Is equatorial or axial more favored?
Substituents prefer equatorial rather than axial positions in order to minimize the steric strain created of 1,3-diaxial interactions. The more stable conformation will place the larger substituent in the equatorial position.
Why do lone pairs prefer equatorial positions?
It is better for the lone pair to be in the equatorial plane because it will have only two 90 degree repulsions from the atoms in the axial plane. Whereas if the lone pair were in the axial plane, it would have three 90 degree repulsions with the atoms in the equatorial plane.
What is the difference between axial and equatorial methyl cyclohexane?
For methylcyclohexane at room temperature (298 K) the 95:5 ratio of equatorial to axial conformers translates to an energy difference of 1.70 kcal/mol. In other words, the equatorial conformer is more stable by 1.70 kcal/mol.
What determines the preference for axial or equatorial position?
The equatorial preference has to do with the fact that one of the two positions, remember that there’s the axial position and there’s the equatorial position, one of them is going to be much more crowded or what we call torsionally strained than the other.
Which chair is more stable?
The chair conformation is more stable because it does not have any steric hindrance or steric repulsion between the hydrogen bonds. By drawing cyclohexane in a chair conformation, we can see how the H’s are positioned.
Are wedges axial or equatorial?
Check it out here. Both are on wedges, both are “up” then, and when drawing the chair conformation, one is axial and another equitorial. In the second set, one substituent is “down” and the other is “up”. When labeling the chair, it turns these two specifically to be both equitorial.
Is equatorial or axial lower energy?
When we do this, here’s what we find. Instead of being equal, the ratio of “equatorial methyl” to “axial methyl” conformers is about** 95:5 favouring the conformation where the methyl group is equatorial. This must mean that the equatorial conformation is of lower energy than the “axial” conformation.
Why are axial positions stable?
When the smaller group (methyl) is axial, the space above the cyclohexane ring is less crowded and so this conformation is energetically more favourable.
How are axial and equatorial positions the same?
It is important to notice that axial positions next to each other point in opposite directions. The same is also true for equatorial positions. This is shown more clearly on the diagram below.
Which is equatorial position face up or down?
The equatorial positions are going to face slightly opposite to the axial. That means – notice this one right here. That one is facing up, that axial. That means that my equatorial position should face slightly down. That means this H, the equatorial one, would face slightly down. Now let’s look at this one.
Where are the equatorial positions on a ring?
Equatorial positions are around the plane of the ring – these are highlighted in blue on the diagram. You can think of these bonds as radiating away from the ‘equator’ of the ring – this will help you remember their name. It is important to notice that axial positions next to each other point in opposite directions.
Where are the axial and equatorial positions of cyclohexane?
In other words, axial chemical bonds are perpendicular to the ring structure of the cyclohexane molecule while the equatorial positions are around the ring structure, oriented away from the equator of the ring. The terms axial position and equatorial position are discussed under the chair conformation structures of organic chemistry.