Vibrational Behavior and Structure of Disulfide Dioxides (Thiolsulfonates)

Infrared and Raman spectra of disulfide dioxides were examined to determine whether they possess the thiolsulfonate or disulfoxide structure. Strong absorptions identified with the SO 2 group support the thiolsulfonate structure. A comparison of infrared spectra of a butyl series of sulfide, sulfoxide, sulfone, sulfinate, sulfonate, disulfide, thiolsulfinate, disulfide dioxide (thiolsulfonate), and α-disulfone confirms the evidence for the thiolsulfonate structure for both the symmetrical and unsymmetrical compounds. With isomeric pairs of mixed disulfide dioxides, the spectra are different in all cases. Where R is CH 3 , there are strong absorptions at 10.4–10.5 and 20.7–20.8 μ only when the methyl is attached to the sulfur atom presumed by synthesis to be in the oxidized SO 2 form. In the reverse isomers, these strong bands, which are associated with CH 3 SO 2 − , are absent.