Q6. Which of the compounds below would give the following IR spectrum?

Background

Topic: IR Spectroscopy and Functional Group Identification

This question tests your ability to interpret IR spectra and match them to the correct organic compound based on characteristic absorption bands.

Key Terms and Formulas

• IR Spectroscopy: A technique used to identify functional groups in organic molecules by measuring absorption of infrared light at specific wavenumbers.

• Characteristic Absorptions:

  • C≡N (nitrile) stretch: cm-1

  • O-H (alcohol/phenol) stretch: cm-1

  • N-H (amine) stretch: cm-1

Step-by-Step Guidance

1. Examine the IR spectrum for key peaks. Notice the strong absorption near $2249$ cm-1, which is characteristic of a nitrile (C≡N) group.

2. Check for other significant peaks. Absence of broad O-H or N-H stretches suggests the compound does not contain alcohol or amine functional groups.

3. Compare the spectrum to the possible answer choices. Focus on which compound contains a nitrile group and lacks O-H or N-H functionalities.

4. Review the molecular structures of the answer choices and identify which one matches the functional group indicated by the IR spectrum.

Try solving on your own before revealing the answer!