A process to for polymerizing ethylene in the presence of a metal complex of Structure I, as described herein, which comprises a metal selected from one of Groups 3-6, which is bonded to aryl groups via oxygen and two Z groups. The aryl groups comprise substituents R1a, R1aa, through R15a, R15aa, which are selected from hydrogen, halo, hydrocarbyl, trihydrocarbylsilyl, trihydrocarbylsilylhydrocarbyl, —O(R), —N(R′R″), —S(R′″), or —P(RIVRV); and each R, R′, R″, R′″, RIV and Rv is described herein. Two X groups are also bonded to the metal, and each is halo, hydrocarbyl, or trihydrocarbylsilyl group. Each Z is O, S, N(C1-C40)hydrocarbyl, or P(C1-C40)hydrocarbyl. Groups Y and L form part of a bridge between the Z groups. Y is halo, hydrocarbyl, trihydrocarbylsilyl, trihydrocarbylsilylhydrocarbyl, —O(RVI), —N(RVIIRVIII), —S(RIX), or —P(RXRXI); and each RVI, RVII, RVIII, RIX, RX and RXI is described herein. L is (C1-C40)hydrocarbylene or (C1-C40)heterohydrocarbylene. The invention also provides Structure I.