Structural implications of the microwave spectrum of hexafluoropropene

Abstract

Analysis of the microwave spectrum of hexafluoropropene, C3F6, has yielded rotational constants for the ground vibrational state of 2557.88, 1255.033, and 987.082 MHz. Assignments have also been made on the first four excited states of the CF3 torsional mode and on the first excited state of another low-lying skeletal mode. A rough estimate of 350 cm−1 has been obtained for the barrier to internal rotation of the CF3 group. The ground-state moments of inertia are consistent with the expected geometry of the molecule, in which all atoms are coplanar except for two equivalent F atoms in the CF3 group.