Chapter 12, Problem 12.9P

Interpretation Introduction

Interpretation:

The fact that the $\text{C-O}$ stretch in ethers and esters occurs at ${\text{1000-1100cm}}^{\text{-1}}$, when the C is ${\text{sp}}^{\text{3}}$ hybridized, but at ${\text{1250cm}}^{\text{-1}}$ when it is ${\text{sp}}^{\text{2}}$ hybridized has to be explained.

Concept Introduction:

The Infrared spectroscopy is used for the determination of functional groups present in the organic compounds.  The IR spectroscopy occurs at the region of ${\text{4000-400cm}}^{\text{-1}}$.  In IR spectroscopy, the absorption occurs at the vibrational level.  At vibrational level, the molecule shows stretching and bending vibrations.  The region used for the determination of functional groups is ${\text{3500-1500cm}}^{\text{-1}}$ (functional group region), as most of the stretching and bending vibrations of functional groups occurs at this region.  The region of ${\text{1500-400cm}}^{\text{-1}}$ is known as finger print region.