Mono- and Bis-acetylidoruthenium(II) Complexes by Controlled Metathesis of Methylruthenium Complexes with Acetylenes

Acetylido methyl ruthenium(II) complexes, trans-Ru(C⋮CR)(CH3)(dmpe)2, were synthesized in a single metathesis reaction from trans-Ru(CH3)2(dmpe)2 at ambient temperature; at elevated temperatures the reaction yields trans-Ru(C⋮CR)2(dmpe)2. Addition of a second terminal acetylene to a methanol solution of trans-Ru(C⋮CR)(CH3)(dmpe)2 results in the formation of trans-Ru(C⋮CR)(C⋮CR‘)(dmpe)2.