Olefin polymerization catalyst system useful for polar monomers

A composition represented by the formula: wherein: M is selected from groups 3-11 of the periodic table; E is nitrogen; AR0 is arene; R1-R4 each independently selected however hydrogen, hydrocarbyl, hydrocarbyl or substituted functional group, with the proviso, that R3 and R4 do not form a naphthyl ring; L1 represents a formal anionic ligand, L2 represents a formal neutral ligand, a is greater than or equal to 1 integer; b is greater than or equal to 0 integer; c is greater than or equal to one integer.