Answer to Question #153894 in Organic Chemistry for leez

Question

The high resolution proton nmr spectrum of propan-1-ol contains four peaks. What is the splitting pattern of the four peaks?

A. 3 2 2 1

B. 3 4 3 1

C. 3 6 3 1

D. 3 6 4 2

Answer 1

Solution:

Suppose the alcohol (propaт-1-ol) is absolutely free of any water, then the hydrogen on the -OH group and any hydrogens on the next door carbon do not interact to produce any splitting.

Using the n+1 rule (the number of sub-peaks in a cluster is one more than the number of hydrogens attached to the next door carbon):

(a): 2+1 = 3 (triplet);

(b): 3+2+1 = 6 (sextet);

(c): 2+1 = 3 (triplet);

(d): 0+1 = 1 (broad singlet).

Hence,

(a,b,c,d) = 3 6 3 1

Answer: C. 3 6 3 1.