In the 1H-NMR spectrum of the following molecule, the signal of proton Ha appears as:
In the 1H-NMR spectrum of the following molecule, the signal of proton Ha appears as:
Show Hint
- singlet
- triplet
- quintet
- quartet
The Correct Option is C
Solution and Explanation
The key to solving this problem is understanding the splitting pattern in 1H NMR due to coupling with neighboring nuclei. Proton \( H_a \) is adjacent to two deuterium atoms (D).
Important points:
- Deuterium (D) has a nuclear spin \( I = 1 \).
- The NMR signal of a proton coupled to \( n \) equivalent nuclei with spin \( I \) will be split into \( (2nI + 1) \) lines.
- Here, \( n = 2 \) deuterons and \( I = 1 \), so:
\[ \text{Multiplicity} = 2 \times 2 \times 1 + 1 = 5 \Rightarrow \text{quintet} \]
Hence, \( H_a \) appears as a quintet.
\[ \boxed{\text{The signal of } H_a \text{ appears as a quintet due to coupling with two deuterium atoms (} I = 1 \text{)}} \]
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