Knowledge Bank

Relatively little is known about the vibrational structure of polycyclic nonbenzenoid molecules. However, a number of interesting features should be observed because of the presence of aromatic and nonaromatic ring systems in the same molecule. The IR spectra of aceheptylene (one 5-membered aromatic ring and two seven-membered nonaromatic rings) and its tetramethyl derivative will be presented and discussed in light of these expectations.