Cyclic aromatic disulfide oligomers: Synthesis and characterization

A series of cyclic aromatic disulfide oligomers have been synthesized in high yields by catalytic oxidization of arenedithiols in DMAc. The aryl groups contain moieties such as ketone, sulfone, isopropylidene, ether, thioether, and phenylphosphine oxide groups. The cyclic aromatic disulfide oligomers have been analyzed by gradient HPLC, GPC, H-1-NMR, MALDI-TOF-MS, DSC, and TGA methods. Repeating units up to 9 for some cyclic aromatic disulfide ketone oligomers have been confirmed by MALDI-TOF-MS. In general, these cyclic aromatic disulfide oligomers are soluble in common organic solvents and have sharp melting points. Cyclic disulfide ketone oligomers and cyclic disulfide sulfone oligomers have higher glass transition temperatures and melting points than their ether or thioether counterparts.