The following problem sets illustrate structure elucidation from IR spectra. Identify the diagnostic absorption bands and hence matches the listed compounds to their proper spectra.
Starting with problem set E - I, list first the expected characteristic absorbencies for an ester, an amide, an amine and an acid. The approach to be used demonstrates the skills needed to approach these problems.
Either benzonitrile or phenylacetonitrile shows a band of medium intensity at 2940 cm-1: the other compound shows nothing in the range 3000—2500 cm-1, explain.
Match the spectra given below to the compounds: Cyclohexadiene, Diphenylacetylene, 1-octene. Identify the diagnostic bands in each spectrum.