Activation of SOF at a Rhodium PNP Pincer Complex: Ligand Supported S-F Bond Cleavage to Generate NSOF Derivatives.

The κ-(P,N)-phosphine ligand precursor NH(CHCHPCy) can be used for the synthesis of the rhodium(I) complex [Rh(CO){ĸ-(P,N,P)-CyPCHNHCHPCy}][Cl] (1). The deprotonated complex [Rh(CO){ĸ-(P,N,P)-CyPCHNCHPCy}] (2) shows a cooperative reactivity of the PNP ligand in the activation reaction of SOF to yield the rhodium fluorido complex trans-[Rh(F)(CO){ĸ-(P,P)-CyPCHN(SOF)CHPCy}] (3) by S-F bond cleavage. It is remarkable that no reaction was observed when 3 was treated with hydrogen sources e. g. dihydrogen, organosilicon compounds such as triethylsilane or TMS-CF and different fluorine sources such as SF or Selectfluor®. However, the treatment of complex 3 with XeF in the presence of CsF resulted in the formation of the unique fluorido rhodium(III) complex cis,trans-[Rh(F)(CO){ĸ-(P,P)-CyPCHN(SOF)CHPCy}] (4). In the presence of pyridine(HF) or BF the fluorido complex 3 converted into the dicationic complexes [Rh(CO){ĸ-(P,P)-CyPCHN(SOF)CHPCy}][XF], X=HF (5) or BF (6), respectively.