Interpreting NMR

Question 1

What is the splitting pattern of the hydrogen labelled a?

Answer 1

Triplet

Question 2

How many 13C peaks are there?

Answer 2

Four

Question 3

How many peaks will form from this molecule? CH3CH2CH=CHCH2CH3

Answer 3

3

Question 4

Identify a solvent in which compounds can be dissolved before obtaining their ‘H NMR spectrum.

Answer 4

CDCl3.

Question 5

How will the peak for the methyl groups be split in this molecule? CH3CH=CHCH3?

Answer 5

Doublet

Question 6

How many C13 peaks are in this spectrum?

Answer 6

9

Question 7

What part of the electromagnetic spectrum does NMR use?

Answer 7

Radio frequency.

Question 8

Which structure would match the 13C spectrum in the diagram? 1,4 dimethyl benzene, 1,3 dimethyl benzene, 1,2 dimethyl benzene or ethyl benzene?

Answer 8

1,3 dimethyl benzene

Question 9

Compound X has the formula C5H10O2. It has three singlets in the ratio 1:3:6. What could it be?

Answer 9

.

Question 10

This is the 13C NMR spectrum of Z. What type of carbon environment causes the peak at δ = 174 ppm?

Answer 10

R-CO- esters

Question 11

This compound is C7H12O3 and has an IR peak at 1720? What is it?

Answer 11

ethyl 4-oxo-butanoate

Question 12

How many H peaks does this molecule have?

Answer 12

2.

Question 13

What is an isomer of the molecule C5H10O which has an ether functional group and 3 13C peaks?

Answer 13

Question 14

Answer 14

Question 15

How many H peaks are there is the beta blocker, atenolol?

Answer 15

10.

Question 16

What is the splitting pattern of the methyl groups in atenolol?

Answer 16

The splitting pattern of this peak is a doublet.

Question 17

Why was CDCl3 used as the solvent for the ‘H NMR spectrum of atenolol?

Answer 17

CDCl3 was used because it is deuterated, which avoids interference in the spectrum.

Question 18

Why is CDCl3 a more effective solvent than CCl4 for polar molecules like atenolol?

Answer 18

CDCl3 is more effective because it can dissolve polar molecules better due to its polarity.

Question 19

What is the splitting pattern of the H peak at 4ppm?

Answer 19

Quartet

Question 20

What was recorded in 2013 related to atenolol?

Answer 20

The 13C NMR spectrum of atenolol was recorded.

Question 21

How many 13C peaks are there in atenolol?

Answer 21

11

Question 22

What is the formula of the compound used as a standard in the NMR spectrum?

Answer 22

The compound that produces the peak at δ = 0 ppm.

Question 23

What is the δ value of the peak produced by the CH3 group in atenolol?

Answer 23

Close to 1ppm.

Question 24

How many CH3 groups are in the structure of atenolol?

Answer 24

There are two CH3 groups in the structure of atenolol.

Question 25

What peak does one of the CH3 groups produce in the 13C NMR spectrum?

Answer 25

The peak at δ = 71 in the 13C NMR spectrum.

Question 26

What is the name of this structure H3Y?

Answer 26

2- hydroxy propane-1,2,3 tricarboxylic acid.

Question 27

Does atenolol have an enantiomer?

Answer 27

Yes.

Question 28

How many peaks would you expect in the 13C spectrum?

Answer 28

Four

Question 29

What is a suggested reducing agent for forming atenolol?

Answer 29

Acidified potassium dichromate

Question 30

What should be circled in the structure of atenolol?

Answer 30

Circle the carbon atom in the structure of atenolol.

Question 31

How can many H peaks do the two isomers have?

Answer 31

2 and 4

Question 32

What is one advantage of using a racemate in medicines?

Answer 32

Suggest one advantage of using a racemate rather than a single enantiomer in medicines.

Question 33

How many 13C peaks are there in each isomer?

Answer 33

Three each.