Problem Set 1 – ¹H NMR Spectra

1. The IR and ¹H NMR spectra of a compound of molecular formula C₁₀H₁₂O are given below.

SDBSWeb: http://www.aist.go.jp/RIODB/SDBS/ (22-12-09)

a. Calculate the degree of unsaturation.

b. List the possible functional groups gleaned from the molecular formula.

c. What is the oxygen-containing functional group that the IR spectrum shows to be present in the unknown?

d. Propose a structure for this compound.

2. The IR and ¹H NMR spectra of a compound of molecular formula C₈H₁₁N are given below.

SDBSWeb : http://riodb01.ibase.aist.go.jp/sdbs/ (National Institute of Advanced Industrial Science and Technology, 27/07/2010)

a. Calculate the degree of unsaturation.

b. List the possible functional groups gleaned from the molecular formula.

c. What is the nitrogen-containing functional group that the IR spectrum shows to be present in the unknown?

d. Propose a structure for this compound.

3. The IR and ¹H NMR spectra of a compound of molecular formula C₉H₁₃N are given below.

SDBSWeb: http://www.aist.go.jp/RIODB/SDBS/ (22-12-09)

a. Calculate the degree of unsaturation.

b. List the possible functional groups gleaned from the molecular formula.

c. What is the nitrogen-containing functional group that the IR spectrum shows to be present in the unknown?

d. Propose a structure for this compound.

4. Sketch the expected ¹H NMR spectrum of the following compound. Pay attention to multiplicity and approximate chemical shifts:

5. Sketch the expected ¹H NMR spectrum of the following compound. Pay attention to multiplicity and approximate chemical shifts:

6. Propose structures for compounds that fit the following data:

a. C₅H₁₀O d = 0.95 ppm (6H, doublet)

d = 2.10 ppm (3H, singlet)

d = 2.43 ppm (1H, multiplet)

b. C₉H₁₁Br d = 2.15 ppm (2H, quintet)

d = 2.75 ppm (2H, triplet)

d = 3.38 ppm (2H, triplet)

d = 7.22 ppm (5H, singlet)