Chapter 15, Problem 15.25YT

Interpretation Introduction

Interpretation:

The stretching absorption bands are to be labeled in the given figure: alkene or aromatic C-H stretches at $\sim \text{3050}\text{}\text{}{\text{cm}}^{\text{-1}}$, alkane C-H stretches between $2800$ and $3000{\text{cm}}^{\text{-1}}$, a $\text{C=O}$ stretches at $\sim 169\text{0}\text{}\text{}{\text{cm}}^{\text{-1}}$ and a $\text{C=C}$ stretches at $\sim 165\text{0}\text{}\text{}{\text{cm}}^{\text{-1}}$.

Concept introduction:

IR spectroscopy enables to identify different functional groups in the molecule.

One of the greatest advantages of IR spectroscopy is that the frequency of a particular type of vibration is typically found within a characteristic range of frequencies, regardless of the functional group with which the vibration is associated. The fact that absorptions by certain vibrations appear with characteristic frequency ranges enables us to use IR spectroscopy to obtain structural information about a molecule.