Studies on the Reactivity of Rh(I) Complexes Towards SF5Cl

Abstract Sulfur chloride pentafluoride reacts with the rhodium(I) NHC complexes (N-heterocyclic carbene) trans- [Rh(Cl)(CO)(IMes)2] (1) and trans- [Rh(F)(CO)(IMes)2] (5) to give the cationic square-pyramidal complexes trans,trans- [Rh(Cl)2(CO)(IMes)2] [SF5] (2) and trans- [Rh(Cl)(F)(CO)(IMes)2] [SF5] (6) at 183 K. The compounds convert into the fluorido complexes trans,trans- [Rh(Cl)2(F)(CO)(IMes)2] (4) and cis,trans- [Rh(Cl)(F)2(CO)(IMes)2] (7) at ambient temperatures. In the reaction of 1 the rhodium(III) fluoroacyl complex trans,trans- [Rh(Cl)2(COF)(IMes)2] (3) was identified as additional product. DFT calculations were carried out in order to determine the configurations of the complexes 2, 3 and 6. For comparison the phosphine complex, trans- [Rh(F)(CO)(PEt3)2] (8) was treated with SF5Cl to yield cis,trans- [Rh(F)2(Cl)(CO)(PEt3)2] (9) at 183 K. At 213 K the sulfanyl complex cis,trans- [Rh(F)2(SF3)(CO)(PEt3)2] (10) was also identified.