Chapter 12, Problem 12.21SP

(a)

Interpretation Introduction

Interpretation:

The IR absorption frequency of a typical $\text{C-D}$ bond is to be calculated.

Concept introduction:

Carbon-deuterium bond is much like a carbon-hydrogen bond. They have similar stiffness which is measured by the spring constant. Due to the extra neutron, the deuterium atom has approximately twice the mass of a hydrogen atom.

The IR absorption frequency of a bond is proportional to $\sqrt{k/m}$ when one of the bonds is heavier than the other.

(b)

Interpretation Introduction

Interpretation:

The functional group that appears to be present in the IR spectrum as a result of the ${\text{CDCl}}_{\text{3}}$ impurity is to be predicted.

Concept introduction:

Carbon-deuterium bond is much like a carbon-hydrogen bond. They have similar stiffness which is measured by the spring constant. Due to the extra neutron, the deuterium atom has approximately twice the mass of a hydrogen atom.