Abstract Hexafluorophosphates of (η 5-pentamethylcyclopentadienyl)(η 6-arene) ruthenium cations (arene= 1, 3, 5-triethylbenzene, 1, 3, 5-tris (trimethylsilylmethyl) benzene, and pentamethylbenzene) have been obtained from the reaction of [Ru (η 5-C 5 Me 5)(NCCH 3) 3]+ PF 6−[Ru (η 5-C 5 Me 5)(NCCH 3) 3]+ PF 6− with the appropriate arene; their X-ray single-crystal structures have been determined and compared to those of related ...