This invention relates to copolymers produced by a polymerization method comprising contacting at least one olefin monomer, at least one polar monomer, an optional activator, and a catalyst compound represented by the formula: ##STR00001## wherein M is selected from groups 3-11 of the periodic table; ##STR00002## L.sup.1 represents a formal anionic ligand, L.sup.2 represents a formal neutral ligand, a is an integer greater than or equal to 1; b is greater than or equal to 0; c is greater than or equal to 1, E is nitrogen or phosphorus, Ar.sup.0 is arene, R.sup.1-R.sup.4 are, each independently, selected from hydrogen, hydrocarbyl, substituted hydrocarbyl or functional group, provided however that R.sup.3 and R.sup.4 do not form a naphthyl ring, N is nitrogen and O is oxygen.