The isomerization reaction from SSF2 to FSSF is studied using the HeI photoelectron spectroscopy (PES) method at 23° C and 50° C. This isomerization reaction is found to be first-order. Kinetic equations for the isomerization reaction at the abovementioned temperatures are, respectively: ln R 296K=−(3.773±0.387)× 10− 5t− 1.840 and ln R 323K=−(8.547±0.978)× 10− 5t− 1.927. The activation energy obtained by the PES ...