Reactivity of Xantphos-Type Rhodium Complexes Towards SF4 : SF3 Versus SF2 Complex Generation.

S-F-bond activation of sulfur tetrafluoride at [Rh(Cl)(tBu xanPOP)] (1; tBu xanPOP=9,9-dimethyl-4,5-bis-(di-tert-butylphosphino)-xanthene) led to the formation of the cationic complex [Rh(F)(Cl)(SF2 )(tBu xanPOP)][SF5 ] (2 a) together with trans-[Rh(Cl)(F)2 (tBu xanPOP)] (3) and cis-[Rh(Cl)2 (F)(tBu xanPOP)] (4) which both could also be obtained by the reaction of SF5 Cl with 1. In contrast to that, the conversion of SF4 at the methyl complex [Rh(Me)(tBu xanPOP)] (5) gave the isolable and room-temperature stable cationic λ4 -trifluorosulfanyl complex [Rh(Me)(SF3 )(tBu xanPOP)][SF5 ] (6). Treatment of 6 with the Lewis acids BF3 or AsF5 produced the dicationic difluorosulfanyl complex [Rh(Me)(SF2 )(tBu xanPOP)][BF4 ]2 (8 a) or [Rh(Me)(SF2 )(tBu xanPOP)][AsF6 ]2 (8 b), respectively. Refluorination of 8 a was possible with the use of dimethylamine giving [Rh(Me)(SF3 )(tBu xanPOP)][BF4 ] (9). A reaction of 6 with trichloroisocyanuric acid (TClCA) gave the fluorido complex [Rh(F)(Cl)(SF2 )(tBu xanPOP)][Cl] (2 b) together with chloromethane and SF5 Cl.