Preparation and reactivity of dichalcogenide (S, Se) dication salts from medium-sized cyclic bis-sulfide and bis-selenides

Article abstract of DOI:10.1016/S0040-4020(01)80348-3

The disulfide dication salt, 1,5-dithioniabicyclo[3.3.0]octane bis(trifluoromethanesulfonate) (3), was isolated from the reaction of 1,5-dithiacyclooctane 1-oxide with trifluoromethanesulfonic anhydride. Two-electron oxidation of 1,5-diselenacyclooctane with two equivalents of NOPF₆ or NOBF₄ gave the first diselenide dication salt, 1,5-diselenoniabicyclo[3.3.0]octane bis(hexafluorophosphate) or bis(tetrafluoroborate) (5). The disulfide and diselenide dication salts (3 and 5) act as an oxidant or as an electrophile depending on the added reagents.