Basic NMR Spectroscopy — Virtual Textbook

Sample NMR Problems

1. You have three unlabeled vials each containing a trichlorobenzene isomer. In order to correctly identify each compound and properly label its container you have taken their ¹³C nmr spectra. Match the spectrum characteristics given below with a compound from the following group:

1,2,3-trichlorobenzene
1,2,4-trichlorobenzene
1,3,5-trichlorobenzene

¹³C NMR:
(i)Two peaks between δ125 and 140 ppm
1,2,3-trichlorobenzene
1,2,4-trichlorobenzene
1,3,5-trichlorobenzene
(ii)Six peaks between δ125 and 140 ppm
1,2,3-trichlorobenzene
1,2,4-trichlorobenzene
1,3,5-trichlorobenzene
(iii)Four peaks between δ125 and 140 ppm
1,2,3-trichlorobenzene
1,2,4-trichlorobenzene
1,3,5-trichlorobenzene

2. You have three unlabeled vials each containing a tetrachlorobenzene isomer. In order to correctly identify each compound and properly label its container you have taken their ¹³C nmr spectra. Match the spectrum characteristics given below with a compound from the following group:

1,2,3,4-tetrachlorobenzene
1,2,3,5-tetrachlorobenzene
1,2,4,5-tetrachlorobenzene

¹³C NMR:
(i)Two peaks between δ125 and 140 ppm
1,2,3,4-tetrachlorobenzene
1,2,3,5-tetrachlorobenzene
1,2,4,5-tetrachlorobenzene
(ii)Three peaks between δ125 and 140 ppm
1,2,3,4-tetrachlorobenzene
1,2,3,5-tetrachlorobenzene
1,2,4,5-tetrachlorobenzene
(iii)Four peaks between δ125 and 140 ppm
1,2,3,4-tetrachlorobenzene
1,2,3,5-tetrachlorobenzene
1,2,4,5-tetrachlorobenzene

3. You have four unlabeled vials each containing a different dichloropropane isomer. In order to correctly identify each compound and properly label its container you have taken their ¹³C nmr and ¹H nmr spectra. Match the spectrum characteristics given below with a compound from the following group:

1,1-dichloropropane 2,2-dichloropropane
1,2-dichloropropane 1,3-dichloropropane

(i)	¹³C NMR: Three signals between δ0 and 60 ppm	¹H NMR: Three signals between δ0 and 5 ppm (the lowest field signal is a sextet)
1,1-dichloropropane 2,2-dichloropropane 1,2-dichloropropane 1,3-dichloropropane

(ii)	¹³C NMR: Two signals between δ0 and 70 ppm	¹H NMR: One signal, a singlet at δ1.2 ppm
1,1-dichloropropane 2,2-dichloropropane 1,2-dichloropropane 1,3-dichloropropane

(iii)	¹³C NMR: Two signals between δ0 and 70 ppm	¹H NMR: Two signals between δ0 and 5 ppm (the lowest field signal is a triplet)
1,1-dichloropropane 2,2-dichloropropane 1,2-dichloropropane 1,3-dichloropropane

(iv)	(iv) ¹³C NMR: Three signals between δ0 and 70 ppm	¹H NMR: Three signals between δ0 and 5 ppm (the lowest field signal is a triplet)
1,1-dichloropropane 2,2-dichloropropane 1,2-dichloropropane 1,3-dichloropropane

← Structurally Equivalent Groups-2

Basic NMR Spectroscopy Discussion →