VIBRATIONAL SPECTRA AND CONFORMATIONS OF SOME SUBSTITUTED CYCLOPROPANE DERIVATIVES

Author Institution:The infrared and Raman of vinyloxirane, epibromihydrin, and (bromomethy1)-cyclopropane have been recorded. The data for the liquid and vapor phases of vinyloxirane are consistent with the presence of three conformations, and the s-trans conformer is more stable than the two non-equivalent gauche forms by $1,1 \pm 0.2$ and $0.8\pm 0.2$ kcal/mole. Epibromohydrin exists primarily as a mixture of two non-equivalent gauche conformers with an enthalpy difference of $0.6\pm 0.2$ kcal/mole, and (bromomethyl) cyclopropane appears to be almost entirely in the gauche form. The stabilities of the cis forms of epibromohydrin and (bromomethyl) cyclopropane will be discussed and vibrational assignments for all three molecules will be presented