Question

which of the structures have a major peak between 1700 and 3000 cm⁻¹? (select all that apply).

Explanation:

Step1: Analyze first - compound

The first compound is an acyl - chloride. The carbonyl group in acyl - chlorides has a stretching frequency around 1750 cm⁻¹, which is in the 1700 - 3000 cm⁻¹ range.

Step2: Analyze second - compound

The second compound is a phenol. The O - H stretching of phenols occurs in the range of 3200 - 3600 cm⁻¹, which is outside the 1700 - 3000 cm⁻¹ range.

Step3: Analyze fourth - compound

The fourth compound is a nitro - compound. The N=O stretching frequencies of nitro - groups are around 1500 - 1600 cm⁻¹ for the asymmetric stretch and 1300 - 1380 cm⁻¹ for the symmetric stretch, which are outside the 1700 - 3000 cm⁻¹ range.

Answer:

The first structure (acyl - chloride)