Organolanthanoids. III. Preparations and properties of some Di(alkynyl)lanthanoids

Abstract

From reactions between di(alkynyl)mercurials and lanthanoid elements in tetrahydrofuran or 1,2-dimethoxyethane, the organolanthanoids (PhCC)2Yb and (PhCC)2Eu(thf)0.25 (thf = tetrahydrofuran) have been isolated, and (RCC)2M (R = Ph or But, M = Yb; R = Ph, M = Eu) characterized in solution. Bis(phenylethynyl)ytterbium has also been obtained by ligand exchange between (C6F5)2Yb or (ButCC)2Y and phenylacetylene. The di(alkynyl)lanthanoids are considered to have associated structures with bridging alkynyl groups. Hydrolysis of (RCC)2M derivatives yields acetylenes RCCH, together with alkenes RCHCH2 (greater for M = Yb than M = Eu), and, when M = Yb, R = Ph, a little ethylbenzene.