Norlutin and Enovid are ketones that suppress ovulation, so they have been used clinically as contraceptives. For which of these compounds would you expect the infrared carbonyl absorption (C=O stretch) to be at a higher frequency? Explain.

These five structures all have distinguishing absorptions in the IR. Match each structure with its characteristic absorption.

(a) sharp, 2254 cm^–1

(b) very broad, centered about 3330 cm^–1

(c) strong, slightly broadened, 1645 cm^–1

(d) broad with spikes at 3367 and 3292 cm^–1

(e) strong, sharp 1717 cm^–1

Three common lab experiments are shown. In each case, describe how the IR spectrum of the product would differ from that of the reactant. Give approximate frequencies for distinctive peaks in the IR spectrum of the reactant and also that of the product.

Give approximate wavenumbers for the major characteristic IR absorption bands that would be given by each of the following compounds:

e.

f.

For each of the following pairs of compounds, name one absorption band that can be used to distinguish between them.

e.

f.

Give approximate wavenumbers for the major characteristic IR absorption bands that would be given by each of the following compounds:

a.

b.

Rank the following compounds from highest wavenumber to lowest wavenumber for their C-O absorption band:

Rank the following compounds from highest wavenumber to lowest wavenumber for their C=O absorption band:

How can IR spectroscopy distinguish between 1-hexyne, 2-hexyne, and 3-hexyne?