Microwave Spectrum of Acryloyl Fluoride

Abstract

The microwave spectrum of $$\begin{array}{ccccccc}& & \mathrm{H}& & \mathrm{F}& & \\ & & |& & |& & \\ {\mathrm{H}}_2\mathrm{C}& =& \mathrm{C}& –& \mathrm{C}& =& \mathrm{O}\end{array}$$ has been studied in the region 8–26 GHz. Two planar rotational isomers have been assigned. Only a‐type transitions have been assigned for ground‐state and first and second torsional excited states of the s‐trans form. Both a‐ and b‐type transitions have been assigned for the ground‐state and first and second torsional excited states of the s‐cis form. The ground‐state energy difference between the two forms was found to be 90 ± 100 cal/mole with the s‐trans the more stable form. The electric dipole moment of the s‐trans form has been found to be 3.26 D oriented 29° from the carbon–oxygen bond. The dipole moment of the s‐cis form was found to be 3.21 D oriented 53° from the carbon‐oxygen bond.