Question

Chair and Boat Conformers of Cyclohexane (C6H12). Note it is impossible to place all the carbons in the same plane without straining the bonds. Take two opposite carbons and pull both of them up to make one conformation and then pull one of them down to make the other conformation.

a. Can you interconvert one conformer into the other without breaking any bonds?
b. Explain why these represent conformers and not isomers.

Answer 1

The chair and boat conformations of cyclohexane represent different spatial arrangements of the carbon atoms in the molecule. It is possible to interconvert one conformer into the other without breaking any bonds through a process called ring flipping. These represent conformers and not isomers because they have the same molecular formula and connectivity, but different spatial arrangements.

Step-by-step explanation:

The chair and boat conformations of cyclohexane represent different spatial arrangements of the carbon atoms in the molecule. In the chair conformation, all carbon atoms are approximately in the same plane and the hydrogen atoms are staggered, resulting in fewer repulsive interactions between them. In the boat conformation, two of the carbon atoms are pulled up and one is pulled down, creating a boat-like shape.

a. It is possible to interconvert one conformer into the other without breaking any bonds. This interconversion is known as ring flipping, where the hydrogen atoms on the axial positions become equatorial and vice versa.

b. These represent conformers and not isomers because they are different spatial arrangements of the same molecule. Conformers have the same molecular formula and connectivity, but differ in the spatial arrangement of their atoms.

Answer 2

See explanation

Step-by-step explanation:

Conformation refers to the various spatial arrangements of atoms in a molecule that result from free rotation across the carbon-carbon single bond.

There are two possible conformations of cyclohexane. They are; the chair and boat conformations.

We can convert the molecule from one conformation to another by rotation of single bonds.

These conformations are not isomers. Isomers are different molecules while conformers are different spatial arrangements of the same molecule obtained by rotation across carbon-carbon single bonds. Isomers are not obtained by rotation across carbon-carbon single bonds.

Hence, the chair and boat conformers of cyclohexane are obtained by rotation across the carbon-carbon single bond hence they are conformers and not isomers.