Alkylidyne complex, dinuclear

The tungsten alkylidyne complexes 141 are reactive toward borane reagents Treatment with BH3 affords the dinuclear complexes 142 [Eq. (128)], and reaction with borabicyclononane gives complex 143 [Eq. (129)]. Complex 143 contains both fragments of the hydroboration reagent attached to the carbyne carbon. 

The dinuclear terminal alkylidyne complexes 163 react with the hydride... 

Efforts by Krouse and Schrock to prepare polyenynes by a metathetical process led to the preparation of several dinuclear complexes bridged by unsaturated bisalkylidyne ligands [Eq. (194)] (199). Two possible reasons for the failure to obtain the desired polymers were mentioned. The dinuclear metal-capped species were found to be thermodynamically more stable than mononuclear complexes with terminal alkylidyne ligands, and the solubility of the oligomers, if formed, appears to decrease rapidly with increasing molecular weight. 

Like other dinuclear complexes containing bridging alkylidyne ligands [5], the chemistry of the Angelici s thiocarbyne [Fe2(ti-CSR)(p-CO)(CO)2Cp2] (l) is dominated by the electrophilic character of the i -carbyne carbon atom. In fact 1 reacts with a variety of nucleophiles such as RS" (R = Me, PhBz), PhSe , BH4" [6] and CN [7] to give the corresponding carbene derivatives 2, 3 and 4 (Scheme 1). 

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