Why Is A Chair More Stable Than A Boat?

Why is a chair more stable than a boat? The chair is more stable because its conformation has no steric hindrance in its Hs. Whereas, the boat conformation has much more steric repulsion in between its two Hs. Besides, the energy in chair conformation is less and in a boat conformation is more.

We know that a staggered conformation is the most stable. Since the chair conformation remains staggered, it is considered more stable. Also, it does not suffer any torsional strain in its C-H bonds like the boat conformation. Thus, a chair is more stable than a boat.

In this article, we will discuss more the chair and boat, their conformation, which one is more stable and less stable, and so on.

Let us not make any further delay and jump to the topic straight.

Keep reading!

Why Is A Chair More Stable Than A Boat?

A chair is more stable than a boat by their conformation. The first and foremost reason is, that a chair conformation has less steric hindrance and a boat conformation has more steric hindrance.

Well, there are other reasons too. Have a look below to know more.

Chair Conformation Is Favored More:

Cyclohexane can be drawn in two ways. Either in conformation or hexagon shape. Among these two confirmation forms, the boat conformation and the chair conformation are the most used.

Because of the steric hindrance, energy, and new hindrance, the drawing of chair conformation is favored over the boat conformation. And since there is a steric repulsion between the two H’s of the boat conformation, the boat conformation drawing is favored less. This is also a reason that it is less stable.

Boat Conformation Is Less Stable:

Anyway, the most stable conformation of cyclohexane is the chair conformation. Just like the chair conformation, the boat conformation does not have any angle strain.

Yet, the boat conformation has the torsional strain and eclipsed bonds in its four C atoms. These are the atoms that form the four sides in the boat conformation.

Besides, the top corners of the boat form go through a steric hindrance. These are the reasons why a boat conformation is less stable.

Energy Is Higher In A Boat Conformation:

The adjacent carbons of C-H bonds in the chair remain staggered. Whereas, the C-H bonds in the boat remain eclipsed.

Besides, it has a revulsion against the flagpole hydrogen (steric hindrance). Its distance is 1.8A, which means the steric hindrance is less. So it’s clear that the energy of the boat is higher than the chair’s energy. Thus, the chair is more stable.

Trans Isomer And Cis Isomer:

If you see a boat’s image, its conformation looks like a trans isomer. Whereas, the chair’s image looks like a cis isomer. And a cis isomer is indeed more stable than a trans isomer. Besides, the prior groups in a cis isomer are on the opposite side.

For this reason, the cis isomer feels minimum repulsion. When an object feels minimum repulsion, it means the object is stable which the trans isomer is not.

Factors That Affect The Stability:

A conformation’s stability differs because of some factors. Such as the angle strain, the torsional strain, and the steric strain. Well, angle strain is the difference between any specific figure and the normal bond angles.

Torsional strain means the two tetrahedral carbons are attached. This is the pair where the bond is staggered. Steric strain is the non-bonded atom, where the vendor walls attract each other.

Repulsive Force:

If we get into a more particular way, boat conformation is less stable than chair conformation because of two reasons. The first reason is, that the boat form has horizontal C-C bonds which show a complete eclipsing.

The second reason is, that there are two hydrogens shown in the boat form that remain for a short distance. Because the distance in the bow strips hydrogen, a repulsive force is formed in the boat conformation.

Chair Conformation Remains Staggered:

The chair conformation has two types of hydrogen, in total twelve hydrogens. Among them, six carbons are joined to those half of the hydrogen in a parallel axis. Whereas, the other half of the six hydrogens roam around the equator in an equatorial design.

It also known these hydrogens as the C-H bonds. The C-H bonds in a chair conformation are equatorial and equally axial. As a result, the chair conformation remains staggered which reduces the torsional strain.

Torsional Strain Prevents Stability:

We can see that the torsional strain in the chair form is less, but in the boat form, it is more.

It’s because the eclipses in the boat form interact with each other. This torsional strain makes the boat conformation suffer from less stability.

Frequently Asked Questions

Why Is Chair Conformation More Stable?

There is no steric repulsion or steric hindrance in a chair conformation’s hydrogen bonds. That’s why the chair conformation is considered more stable. Cyclohexane in a chair form has its H positioned stably.

Why Is The Half Chair The Least Stable?

A half chair does not have six of six C atoms. It has five atoms. Also, it raises the footrest on the chair which enhances the bond angle strains and eclipsing. For this reason, a half chair is the least stable.

What Is The Least Stable Conformation of Cyclohexane?

Boat conformation is the least stable of the cyclohexane since it has a steric hindrance in between the hydrogens, i.e. carbon 1 and carbon 4. Another reason the boat conformation is less stable is that it has the highest strength and torsional stress.

Why Is Boat Conformation Less Stable?

In a boat conformation, there is a torsional strain in the cyclohexane molecule. For this torsional strain, the boat conformation is not so stable.

Again, the hydrogen atoms in it have an interaction of steric strain. This is also a reason the boat conformation lacks stability.

What Are The Chair And Boat Conformation of Cyclohexane?

In cyclohexane forms, the chair conformation is the most stable. So it is inevitable that the chair conformation is more stable than the boat conformation.

Sometimes, the boat conformation can be more stable, but not than the chair conformation because it goes through a slight rotation.

Conclusion

Hopefully, the above article could make you understand why is a chair more stable than a boat. We have already said in the introduction that a conformation that remains staggered, is the most stable.

In the same way, a chair’s C-H bonds are staggered at the adjacent carbons. But the C-H bonds in a boat conformation are eclipsed. Thus, a chair is stable, and a boat is not.

Also, the steric hindrances between the flagpole hydrogens, make the boat conformation less stable than the chair conformation.

So this was all about the chair, boat, their stability, and their confirmation. Let us know through the comment section below if you have any queries.

Thank you.