PENTACOORDINATED SULFUR(VI) SALTS

Pentafluorosulfanylamines, R2NSF5 (R2N=Et2N, piperidyl) react with AsF 5 to give stable persulfuranonium hexafluoroarsenates, Et2NSF4+AsF6- ( 4) and Pip-SF4+AsF6- (5), respectively. At low temperatures, SF5NS(O)F 2 forms an unstable adduct SF5NS(O)F2.AsF5 (12), which dissociates rev ersibly into the starting materials on warming, while the correspondin g SF5NSF2.AsF5 (14) is readily decomposed in liquid SO2 to give OSF2 a nd AsF5.NSF3 (15). In the absence of solvent and in the presence of ex cess AsF5, slow decomposition to SF3+AsF6- and 15 was observed. [(Me2N )2SF2]2+(AsF6-)2 (16) adds HF with the formation of a salt containing a pentacoordinated sulfur(VI) dication, [Me2N-SF3-NMe2-H)2+ (AsF6-)2 ( 17).