What is the dihedral angle between two gauche groups in a Newman projection?

For each pair of conformations shown, choose which is most stable. [If both conformations have the same number of gauche interactions, choose the one where the interactions are between smaller groups.]

(f)

Which of the following structures represent the same compound? Which ones represent different compounds?

(f)

Construct a graph, similar to Figure 3-11, of the torsional energy of 3-methylpentane along the C2―C3 bond.

a. Place C2 in front, represented by three bonds coming together in a Y shape, and C3 in back, represented by a circle with three bonds pointing out from it.

b. Define the dihedral angle as the angle between the methyl group on the front carbon and the ethyl group on the back carbon.

Calculate the dihedral angle (θ) for the conformations shown.

(c)

Which of the following conformers of isobutyl chloride is the most stable?

Construct a graph, similar to Figure 3-11, of the torsional energy of 3-methylpentane along the C2―C3 bond.

c. Begin your graph at the 0° dihedral angle and begin to turn the front carbon.

Draw a graph, similar to Figure 3-11, of the torsional energy of 2-methylbutane as it rotates about the C2—C3 bond.

Draw a graph, similar to Figure 3-9, of the torsional strain of 2-methylpropane as it rotates about the bond between C1 and C2. Show the dihedral angle and draw a Newman projection for each staggered and eclipsed conformation.