Embodiments of this disclosure include processes of polymerizing olefins, the process comprising contacting ethylene and a (C3-C40)alpha-olefin comonomer in the presence of a catalyst system, the catalyst system comprising a Group IV metal-ligand complex and an ionic metallic activator complex, the ionic metallic activator complex comprising an anion and a countercation, the anion having a structure according to formula (I):formula (I)