Constrained geometry complexes—Synthesis and applications

Transition metal complexes bearing linked cyclopentadienyl amido ligands, regularly referred to as constrained geometry complexes (CGCs), have found wide interest both in academia and industry since their first description in 1990. Particularly, Group 4 CGCs were applied as catalyst precursors for the polymerisation of α-olefins, often yielding polymers with unique microstructure and material properties. Moreover, the potential of CGCs to mediate transformations other than polymerisation reactions is increasingly acknowledged. The present review aims to give a comprehensive survey about the chemistry of CGCs and covers reports in the open literature between 1990 and spring 2005.