Bis(trimethylphosphine)silver(I) hexafluorophosphate.

In the title two-coordinate silver compound, [Ag(C3­H9­P)2]­PF6, the cation has crystallographically imposed mirror symmetry, and approximates very closely to \overline 3m (D3d) symmetry with fully staggered methyl groups in the solid state. The Ag atom has a nearly linear coordination geometry, with a P—Ag—P angle of 178.70 (4)°. The Ag—P bond lengths are 2.3746 (12) and 2.3783 (12) A, which are ­significantly longer than the Au—P bond length of 2.304 (1) A in the analogous two-coordinate gold cation. The lack of intra­molecular steric effects within the present cations containing tri­methyl­phosphine (cone angle 118°), compared with those in known cations containing trimesityl­phosphine (cone angle 212°), provides a better comparison of M—P distances and thus more conclusive evidence that Au really is smaller than Ag.