Vibrational spectra of cyclopropyl cyanide and cyclopropyl cyanide-α-d1

Raman spectra of cyclopropyl cyanide-α-d1 (CPCN-d) in its condensed phases have been recorded for the first time, along with the solid-phase Raman spectrum of the parent compound, cyclopropyl cyanide (CPCN). In addition, liquid-and solid-phase infrared spectra were obtained for the isotopic derivative, and gas-phase Fourier transform infrared spectra were obtained for both compounds. The date for CPCN-d, combined with information deduced from gas-phase infrared band contours and Raman depolarization ratios, enable vibrational assignments to be proposed for 47 of the 48 normal modes of these two molecules. Strong mixing of several modes in CPCN is revealed by the deuterium labeling, and evidence for self-association in the condensed phases is discussed. The vibrational frequencies and assignments are compared with similar results for other cyanide- and halogen-substituted cyclopropanes. (author)