Question

question 5
what stretching frequencies (in cm⁻¹) are present in the structure below?
1750
1685
1715

Explanation:

Step1: Identify the functional - group

The structure is an ester (aromatic - oxygen - carbonyl group).

Step2: Recall the carbon - oxygen double - bond ($C=O$) stretching frequency of esters

The $C = O$ stretching frequency of esters is typically in the range of 1735 - 1750 $cm^{-1}$ for saturated esters and around 1715 - 1730 $cm^{-1}$ for aromatic esters. In this case, it is an aromatic ester.

Answer:

1715