Vibrational spectra of 3-fluorocyclopropene-d0 and -d3

Infrared and Raman spectra of 3-fluorocyclopropene-d0 and -d3 have been recorded. Complete assignments of the vibrational fundamentals for these two isotopic species are proposed. For the d0 species the fundamentals (in cm^-^1) are: (a\u27) 3162, 3032, 1623, 1324, 1200, 956, 936, 660, 457; (a\u27\u27) 3122, 1060, 1037, 876, 860, 446. By means of an overlay normal coordinate calculation involving the six isotopomers of 3-chlorocyclopropene as well as the two isotopomers of 3-fluorocyclopropene, empirical force constants for 3-fluorocyclopropene have been fitted. Approximate descriptions of the normal modes are proposed on the basis of the normal coordinate calculations as well as group frequency considerations. Force constants for stretching C C and C C bonds are comparable for these two halocyclopropenes