Splitting of a signal in a proton NMR spectrum tells us the number of chemically

Question

Splitting of a signal in a proton NMR spectrum tells us the number of chemically non-equivalent hydrogens in the Predict the number of lines exhibited by hydrogens at the labeled positions in a first-order NMR spectrum. (Make the ation that all coupling constants are equal.) 1) OCH 3 The number of lines exhibited by hydrogen(s) a is The number of lines exhibited by hydrogen(s) b is The number of lines exhibited by hydrogen(s) c is 2) a The number of lines exhibited by hydrogen(s) a is The number of lines exhibited by hydrogen(s) b is The number of lines exhibited by hydrogen(s) c is

Explanation / Answer

No. of lines depends upon the environment of the protons. Chemically equivalent protons gives single line without any splitting.Only chemically non equivalent protons coulpe with vicinal protons and gives splitting by simple (n+1) rule.

1) a

a is CH3 it has three H and all are chemically equivalent and also there is no vicinal H so it will give only one line (singlet).

1) b

b has only one H but in vicinity there are two H so it will couple with this and will give triplet.

1) c

c has two H both are chemically equivalent so it will couple with vicinal protons(one on olefenic carbon and another adjascent to Oxygen) and gives triplet.

2) a

a has three hydrogens all are chemically equivalent and have no vicinal protons resulted only one line(singlet).

2)b

b has two protons both are chemically equivalent but they have vicinal three protons so they will couple and give quartet.

2)c

c has three protons and all are chemically equivalent but they have vicinal two protons so they will couple and give triplet.

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.