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.

 

(2 x 10 – 12 + 2)/2 = 5

 

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

 

Alcohol, aldehyde, ether, ketone, phenol

 

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

 

Ketone

 

d.    Propose a structure for this compound.

 

 

 

  1. 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.

 

(2 x 8 + 1 – 11 + 2)/2 = 4

 

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

 

Nitrile, primary amine, secondary amine, tertiary amine

 

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

 

Primary amine

 

d.    Propose a structure for this compound.

 

 

  1. 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)

 

d.    Calculate the degree of unsaturation.

 

(2 x 9 + 1 – 13 + 2)/2 = 4

 

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

 

Nitrile, primary amine, secondary amine, tertiary amine

 

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

 

Primary amine

 

g.    Propose a structure for this compound.

 

 

 

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

 

 

 

 

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

 

 

           

 

  1. 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)