New Types of (Arene)ruthenium Alkynyl Complexes

Abstract

The reaction of [{RuCl(cym)}2(μ-Cl)2] (cym = η6-4-methylisopropylbenzene) with 1,10-phenanthroline and NaBAr‘4 (Ar‘ = 3,5-bis(trifluoromethyl)phenyl), followed by addition of excess sodium acetylide, yielded the complex [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)(phen)]BAr‘4 (3) complexes were prepared in an analogous manner from the corresponding lithium acetylides and in situ generated ruthenium triflate precursors. Protonation of 1 with HOTf afforded the acyl complex [Ru(C(O)CH3)(cym)(phen)]BAr‘4 (4), presumably by reaction of an initially formed dicationic 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 characterized by IR and NMR, and the crystal structures of 1, 4, and 5 were determined by X-ray diffraction.