AN ABINITIO VIBRATIONAL STUDY OF ROTATIONAL-ISOMERISM IN OXALYL FLUORIDE, O=CF-CF=O, AND ACRYLOYL FLUORIDE, O=CF-CH=CH2

Results of complete geometry optimizations of the rotational isomers of oxalyl fluoride and acryloyl fluoride at a variety of computational levels are reported. These molecules are found to have planar s-trans (anti) and s-cis (syn) conformations. The RHF/6-31G//RHF/6-31G harmonic force fields of these molecules are calculated as analytical second derivatives, and the vibrational frequencies are obtained from the corresponding scaled quantum mechanical force fields. Some reassignments of fundamental frequencies are suggested. © 1990.