“…75 °C, where the peaks coalesce and the compounds decompose, leaves the distinction between 1 and 2 unresolved. To be sure, S 2 (OCH 2 R) 2 analogues are in the disulfide form in the gas phase 3c and the solid state. 3b, However, the low barriers to rotation about S−O and S−S bonds (6−9 ,9b and 8−10 ,, kcal/mol, respectively), the existence of isomers for S 2 F 2 , and the capacity for isomerization of FSSF to F 2 SS above −100 °C continue to suggest the possibility that 1 rearranges to branch-bonded valence isomer 2 in solution 7b. The latter would display diastereotopic methylene protons at ambient temperature and carries the potential for NMR coalescence due to inversion at S(S).…”