COMBINATION BAND STUDIES OF CYCLIC COMPOUNDS

Abstract

Several sum and difference bands resulting from the combination of the ring-puckering vibration with other vibrational modes have been observed in the mid-infrared spectra of some cyclic molecules including silacyclobutane and silacyclopent-3-ene. These data are analyzed with the help of the available far-infrared spectra to estimate the ring-puckering energy levels in the excited states of other vibrations. Although these differ little from those in the ground state, combination bands can nevertheless be difficult to interpret if the far-infrared data are not available.