The reaction of [{RuCl(cym)}(2)(mu -Cl)(2)] (cym eta (6)-4-methylisopropylb
enzene) with 1,10-phenanthroline and NaBAr'(4) (Ar' = 3,5-bis(trifluorometh
yl)phenyl), followed by addition of excess sodium acetylide, yielded the co
mplex [Ru(CCH)(cym)(phen)]BAr'(4) (1), the first cationic (arene)ruthenium
alkynyl. Similar [Ru(CCPh)(cym)(phen)]BAr'(4) (2) and [Ru(CCSiMe3)(cym)(phe
n)]BAr'(4) (3) complexes were prepared in an analogous manner from the corr
esponding lithium acetylides and in situ generated ruthenium triflate precu
rsors. Protonation of 1 with HOTf afforded the acyl complex [Ru(C(O)CH3)(cy
m)(phen)]BAr'(4) (4), presumably by reaction of an initially formed dicatio
nic vinylidene with adventitious water. The reaction of [RuCl2-(cym)(PMe3)]
with excess LiCCPh afforded the complex [Ru(CCPh)(2)(cym)(PMe3)] (5), the
first (arene)ruthenium bis(acetylide) complex. All new compounds were chara
cterized by IR and NMR, and the crystal structures of 1, 4, and 5 were dete
rmined by X-ray diffraction.