VIBRATIONAL SPECTRA AND CONFORMATIONS OF (IODOMETHYL) CYCLOPROPANE DERIVATIVES

The infrared and Raman spectra of (iodomethyl) cyclopropane and epiiodohydrin have been studied in the fluid and solid phase, (Iodomethyl) cyclopropane exists in a gauche conformation, and no evidence of a second conformer was found. Epiiodohydrin (iodomethyloxirane) has been found to exist as at least two conformations in the liquid state. The gauche$-1$ and gauche$-2$ conformations are separated by $0.50 \\pm 0.10 $kcal/mole with the former being the more stable. In the solid state, the Raman spectrum exhibits bands for the gauche$-1$ conformer, but previously reported infrared spectra indicate that either form may exist in the solid state. The conformational equilibria in this molecule and its relationship to the other epihalohydrins will be discussed.