Polymerization processes for high molecular weight polymers

A process to form an ethylene-based polymer, said process comprising at least the following:

• polymerizing ethylene in the presence of a metal complex selected from Structure I below:
• wherein:
• M is a metal selected from Group 3, Group 4, Group 5 or Group 6 of the Periodic Table of the Elements;
• R1a, R1aa, R2a, R2aa, R3a, R3aa, R4a, R4aa, R5a, R5aa, R6a, R6aa, R7a, R7aa, R8a, R8aa, R9a, R9aa, R10a, R10aa, R11a, R11aa, R12a, R12aa, R13a, R13aa, R14a, R14aa, R15a, R15aa, independently in each occurrence, is hydrogen, halo, hydrocarbyl, trihydrocarbylsilyl, trihydrocarbylsilylhydrocarbyl, —O(R), —N(R′R″), —S(R′″), or —P(RIVRV);
• and wherein each R, R′, R″, R′″, RIV and RV is independently hydrogen, a C1-C18 aliphatic hydrocarbyl, or a C1-C18 heterohydrocarbyl;
• each X is independently selected from halo, hydrocarbyl, or trihydrocarbylsilyl group;
• each Z is independently selected from O, S, N(C1-C40)hydrocarbyl, or P(C1-C40)hydrocarbyl;
• Y is selected from halo, hydrocarbyl, trihydrocarbylsilyl, trihydrocarbylsilyl-hydrocarbyl, —O(RVI), —N(RVII RVIII), —S(RIX), or —P(RXRXI);
• and wherein each RVI, RVII, RVIII, RIX, RX and RXI is independently hydrogen, a C1-C18 aliphatic hydrocarbyl or a C1-C18 heterohydrocarbyl;
• L is —CH2CH2CH2.