Bis(acetylide) complexes of ruthenium

Complexes of the form [Ru(CCR′)2(L–L)2][L–L = R2PCH2CH2PR2; R = Me (dmpe) or Et (depe); R′= But, Ph, 4-HCCC6H4, 4-MeOC6H4 or 3,5-(F3C)2C6H3] were prepared by reaction of [RuCl2(L–L)2] or [RuH2(L–L)2] with terminal acetylenes in methanol solution. The spectroscopic data indicate that the acetylide groups adopt a trans stereochemistry across the metal centre. The crystal structure of [Ru(CCPh)2(dmpe)2] was determined.