The preparation and some reaction of F2PSPF2 and F2PC(CF3)2OPF2, and the synthesis of the bis-borane adduct of F2PSSPF2

Abstract

The potentially bidentate fluorophosphine ligand F2PSPF2 can be prepared in 75% yield from the reaction of F2PBr and [(C4H9)3Sn]2S. On the basis of infrared and Raman spectra, the compound has been assigned a bent confirmation of point Cs or C2. Nuclear magnetic resonance data confirm the assigned formula; but, as indicated by Rudolph and Newmark, low rigidity in the P-S-P backbone is probable and several rotamers might be expected. The compound is pyrophoric in air, but decomposes slowly at 25[deg] and low pressure in the absence of air and water. It reacts with HCl and H2O. With an excess of B2H6 at room temperature it gives the of the formerly elusive disulfide F2PSSPF2. The free disulfide has not yet been obtained from the adduct. A related fluorophosphine bidentate ligand, F2PC(CF3)2OPF2 was prepared in 80% yield from the reaction of P2F4 and hexafluoroacetone. The compound can be unequivocally characterized from its 19F nmr spectrum alone, although other data are given.