Reversible Oxidative Se-Se Coupling of Phosphine Selenides by Ph Sb(OTf).

Salts of diphosphoniumdiselenide dications ([R PSeSePR ][OTf] ) have been isolated from reactions of trialkylphosphine selenides with triphenylantimony bistriflate. The redox process is speculated to proceed via a cationic coordination complex [Ph SbL ][OTf] (L=Me PSe, iPr PSe), which is also formed in the reaction of [R PSeSePR ][OTf] with Ph Sb. The observations indicate that the reductive elimination of [R PSeSePR ] from [Ph Sb(SePR ) ] is reversible through the oxidative addition of [R PSeSePR ] to Ph Sb.