Knowledge Bank

“The infrared spectra of cyclopentane, cyclopentene, cyclohexane, eyclohexene, tetrahydropyran, dihydropyran, p-dioxane, trioxane and quinolizidine have been examined in the interval 650 to $5000cm-1$. Skeletal frequencies from 100 to $250cm-1$ are observed in combination and difference with the ring stretching fundamental (850 to $1000cm-1$), with the $C=C$ stretching fundamental and with their overtones. The number of skeletal frequencies is consistent with the symmetry of the molecule.”