Question

What is the splitting pattern of proton $H^{a}$ of the following compound in its $^1H NMR$ spectrum?

• A. Doublet
• B. Doublet of doublet
• C. Multiplet
• D. Triplet

Answer 1

The Correct Option is D

To determine the splitting pattern of proton H^a in the given compound's ^1H \space NMR spectrum, we can use the N+1 rule. This rule states that the splitting pattern of a proton is determined by the number of neighboring protons (N) plus one.

1. Identify the neighboring protons: Proton H^a is adjacent to two equivalent protons on the CH₂ group.
2. Apply the N+1 rule: Here, N = 2 (as H^a is adjacent to 2 protons). Thus, the splitting pattern will be N + 1 = 2 + 1 = 3.
3. Determine the splitting pattern: With 3 peaks, the splitting pattern of proton H^a is a triplet.

Hence, the correct answer is Triplet.

Other options explained:

• Doublet: Would be observed if H^a had one adjacent proton.
• Doublet of doublet: Would occur if there were two sets of non-equivalent protons.
• Multiplet: Arises from complex splitting, indicating more complex relationships than found here.