Chapter 4, Problem 55PP

Interpretation Introduction

Interpretation:

Energy diagram for conformational analysis of 2,2,3,3-tetramethylbutane should be sketched and also the energy difference between staggered and eclipsed conformations are needed to find out using table 4.6.

Concept introduction:

Conformational analysis is the study of energy verses different conformers. Conformers arise due to the free rotation of $\text{C}-\text{C}$ bond. This rotation are measured by dihedral angle, it is the angle between two atoms attached to two different carbons of $\text{C}-\text{C}$ rotation in Newman projection.

Newman projection: Newman projection of molecule is one type of representations for the alkanes, where the projection visualization from one carbon to another carbon. In this Newman projection, front carbon which represented as dot is called proximal and the back carbon which represented as circle is called distal.

The most and least energy occupied conformers are eclipsed and staggered, which are having a dihedral of ‘0’ and ‘60’ degree respectively.

If the energy levels of different eclipsed conformers or staggered conformers are same then they are called degenerated.

For eclipsed conformations, Torsional strain and steric interactions of atoms are the energizing factors.

For staggered conformations, anti-interactions and gauche interactions of atoms are the energizing factors.

Table 4.6

To sketch and find: the energy diagram for conformational analysis of 2,2,3,3-tetramethylbutane and energy difference between staggered and eclipsed conformations.