FT-IR SPECTRA OF XENON SOLUTIONS OF C-C3H5CFO AND CH2CHCFO

The infrared (3500-400 cm(-1)) spectra of cyclopropylcarbonyl fluoride , c-C3H5CFO, and propenoyl fluoride, CH2CHCFO, in xenon solutions have been recorded al various temperatures (from -60 to -100 degrees C). T he data show that there is an equilibrium between the cis (oxygen atom of the carbonyl bond cis with respect to the ring or carbon-carbon do uble bond) and trans conformers in the fluid phases. Analysis of the t emperature-dependent spectra shows the cis conformer is the more stabl e rotamer for the cyclopropyl compound whereas the trans rotamer is th e more stable conformer for propenoyl fluoride.