Discussion
In the 1H NMR spectrum, which one of the following compounds will show a triplet?
- A.
- B.
- C.
- D.
Answer: A
The key gives (A), ethyl acetate.
In ethyl acetate the OCH2 protons and the CH3 of the ethyl group are the classic pair: the CH3 is split by two neighbouring protons into a triplet (the CH2 is a quartet), while the acetyl CH3 is a singlet. Acetone (B) gives one singlet for its six equivalent protons. 4-Bromophenol (D) has a symmetrical para ring, which gives two doublets, and an OH singlet.
Option (C), methyl 3,5-dichlorobenzoate, is a doubt. Its 4-H has two equivalent meta neighbours, so it appears as a finely split triplet with a coupling of only about 2 Hz, and it is also a triplet by the splitting rule. The key rests on the textbook reading of "triplet" as the vicinal ethyl triplet, so (A) is the keyed answer.
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development