Synthesis and Characterization of the Dodecahexaynediyldiiron Complex, Fp*−(C⋮C)6−Fp* [Fp*= Fe(η5-C5Me5)(CO)2], the Longest Structurally Characterized Polyynediyl Complex

Cu-catalyzed oxidative coupling of the hexatriynyl complex Fp*−(C⋮C)3−H affords the dodecahexynediyl diiron complex Fp*−(C⋮C)6−Fp*. Its linear but slightly twisted structure has been revealed by X-ray crystallography.