The infrared spectra of 2-chlorocyclobutanone and 2-chloro-2,4,4-trideuterocyclobutanone in the liquid and vapor phases have been recorded from 4000 to 250 cm-1. The far-infrared spectrum of 2-chlorocyclobutanone vapor has been recorded from 33 to 600 cm-1. The Raman spectra of the two isotopic species in the liquid state have also been measured. An assignment of the fundamental vibrational frequencies is presented. The ring-puckering mode gave rise to lines at 178 and 170 cm-1 in the Raman spectrum of 2-chlorocyclobutanone and 2-chloro-2,4,4-trideuterocyclobutanone, respectively, and the qualitative nature of the potential function governing this vibration is discussed. The NMR spectra of both isotopic species have likewise been recorded. From the interpretation of the data, the 2-chlorocyclobutanone molecule appears to be essentially planar with only one geometrical configuration which is in marked contrast to the conformers previously reported for this molecule. © 1968.
