15. Analytical Techniques:IR, NMR, Mass Spect

For the following molecules, give the integration you would expect for the signal associated with the hydrogens at the labeled carbons. [Pay attention to the symmetry, or lack of symmetry, in the molecules.]

(f)

Determine the ratios of the chemically nonequivalent protons in a compound if the steps of the integration curves measure 40.5, 27, 13, and 118 mm, from left to right across the spectrum. Draw the structure of a compound whose ¹H NMR spectrum would show these integrals in the observed order.

For the following molecules, give the integration you would expect for the signal associated with the hydrogens at the labeled carbons. [Pay attention to the symmetry, or lack of symmetry, in the molecules.]

(e)

Complete the table of ¹H NMR data you'd generate for each of the following molecules.

(d)

For the molecules shown, give the number of signals expected and the relative ratio of the signal integrations.

(b)

How would integration distinguish the ¹H NMR spectra of the following compounds?

Being able to recognize patterns of integration and multiplicity for common functional groups makes structure identification more efficient. Draw the pattern of integration and multiplicity you'd expect to see for each common alkyl group.

(d)

For the following molecules, give the integration you would expect for the signal associated with the hydrogens at the labeled carbons. [Pay attention to the symmetry, or lack of symmetry, in the molecules.]

(c)

For the compound shown, produce a table of the shift, integration, and multiplicity of each peak you would expect to see in a ¹H NMR spectrum.

Draw the peak that would correspond to the hydrogens at C₃ in the molecule shown. Be sure to indicate the integration and place it at an appropriate chemical shift.

Being able to recognize patterns of integration and multiplicity for common functional groups makes structure identification more efficient. Draw the pattern of integration and multiplicity you'd expect to see for each common alkyl group.

(c)

Complete the table of ¹H NMR data you'd generate for each of the following molecules.

(c)

PRACTICE: Which of the following molecules gives a 1H NMR spectrum consisting of three peaks with integral ratio of 3:1:6 (when signals are counted from left to right)?

Complete the table of ¹H NMR data you'd generate for each of the following molecules.

(b)