Carbene ligands, esp. N-heterocyclic carbenes (NHC), are widely used in late transition metal catalysts,
often enhancing catalytic activity due to their strong σ-donation ability helping to stabilize the active species. In
contrast, limited examples of early transition metal catalysts contg. NHCs have been reported, esp. group 4
olefin polymn. catalysts, due to their poor binding affinity to early transition metals. Indeed, the increasing
interest in "post-metallocene" catalysts for olefin polymn. has generated many active catalysts that exploit
the modularity of the ligand to afford in particular interesting tacticity control. In this regard, we are
investigating the use of tridentate dianionic carbenes bearing bisphenolate arms as ligands for olefin polymn. In
this talk, we will present the coordination chem. of these new carbenes with group 4 metal complexes and
their application as catalysts for the polymn./oligomerization of α-olefins