Raman and infrared spectra and ab initio calculations for the determination of the conformational stability for fluorocarbonyl and acetyl isocyanate

Abstract The infrared and Raman spectra of gaseous, liquid and solid fluorocarbonyl isocyanate, FC(O)NCO, and acetyl isocyanate, CH 3 C(O)NCO, have been recorded. From these data the conformational stability has been determined for both molecules for all three physical states. The conformational energy differences, optimized geometries, and fundamental vibrational frequencies have also been obtained from ab initio calculations.