Formation of hypercoordinated carbon inside a (mu-hydrocarbyl)bis(group 4 metallocene) framework by a simple protonation route

A simple protonation route has been devised for the first time which makes the formation of hypercoordinated carbon geometries synthetically available inside a (mu-hydrocarbyl)bis(group 4 metallocene) complex framework. Readily available neutral dimetallic (mu-alkenyl)-bis(zirconocene) complexes are used as precursors. The developed hydrocarbyl ligands contain hypercoordinated carbon derived from the distorted square-pyramidal CX5 geometry. Results suggest that the combined features of the two group 4 metallocene units have made the hypercarbon structure stable.