Ferrocenium hexafluorophosphate is an organometallic compound with the formula [Fe(C5H5)2]PF6.

This salt is composed of the cation [Fe(C5H5)2]+ and the hexafluorophosphate anion (PF−6).

In acetonitrile solution that is 0.1 M in NBu4PF6, the Fc+/Fc couple is +0.641 V with respect to the normal hydrogen electrode.

[3] Commercially available, this compound may be prepared by oxidizing ferrocene with ferric salts followed by addition of hexafluorophosphoric acid.

[3] The compound is monoclinic with well-separated cation and anion; the PF−6 may rotate freely.