Attempted crystallization of (H2IMes)RuCl2(P(CH2CH2Rf8)3)(=CHPh) (H2IMes = 1,3-dimesityl-4,5-dihydroimidazol-2-ylidene; Rf8 = (CF2)7CF3) in air affords dark red needles of the octahedral ruthenium(III) salt [H3IMes]+trans-[RuCl4(P(CH2CH2Rf8)3)2]−, which is structurally characterized. Only crystal structures of square planar adducts of fluorous alkylphosphines have been determined to date. The bond lengths and angles associated with the cation and RuCl4L2 core are similar to those in related compounds. The lattice exhibits fluorous domains unlike those in square planar complexes, and the ponytail conformations are analyzed in detail. The NCHN proton of the cation is hydrogen bonded to two chloride ligands of the anion, and the CH2CH2 “backside” is directed at two chloride ligands of another anion, leading to non-fluorous channels in the lattice.