Procatalyst and polymerization process using the same

A polymerization process for producing ethylene based polymers comprising polymerizing ethylene and optionally one or more a-olefins in the presence of a catalyst system in a reactor system having one or more reactors, wherein the catalyst system comprises

• one or more procatalysts comprising a metal-ligand complex of formula (I) below:
• wherein:
• M is titanium, zirconium, or hafnium, each independently being in a formal oxidation state of +2, +3, or +4;
• and n is an integer of from 0 to 3, and wherein when n is 0, X is absent;
• and
• each X independently is a monodentate ligand that is neutral, monoanionic, or dianionic;
• or two Xs are taken together to form a bidentate ligand that is neutral, monoanionic, or dianionic;
• and X and n are chosen in such a way that the metal-ligand complex of formula (I) is, overall, neutral;
• and
• each Z independently is O, S, N(C1-C40)hydrocarbyl, or P(C1-C40)hydrocarbyl;
• and
• L is (C2-C40)hydrocarbylene or (C2-C40)heterohydrocarbylene, wherein the (C2-C40)hydrocarbylene has a portion that comprises a 2-carbon atom to 10-carbon atom linker backbone linking the Z atoms in formula (I) (to which L is bonded) and the (C2-C40)heterohydrocarbylene has a portion that comprises a 3-atom to 10-atom linker backbone linking the Z atoms in formula (I), wherein each of the 3 to 10 atoms of the 3-atom to 10-atom linker backbone of the (C2-C40)heterohydrocarbylene independently is a carbon atom or heteroatom, wherein each heteroatom independently is O, S, S(O), S(O)2, Si(RC)2, Ge(RC)2, P(RP), or N(RN), wherein independently each RC is selected from the group consisting of (C1-C40)hydrocarbyl, each RP is (C1-C40)hydrocarbyl;
• and each RN is (C1-C40)hydrocarbyl or absent;
• and
• R1-16 are each independently selected from the group consisting of a (C1-C40)hydrocarbyl, (C1-C40)heterohydrocarbyl, Si(RC)3, Ge(RC)3, P(RP)2, N(RN)2, ORC, SRC, NO2, CN, CF3, RCS(O)—, RCS(O)2—, (RC)2C═N—, RCC(O)O—, RCOC(O)—, RCC(O)N(R)—, (RC)2NC(O)—, halogen atom, hydrogen atom, and any combination thereof, provided that at least one of the R1-R16 is —Si(Y1)(Y2)(Y3) or (C1-C40)heterohydrocarbyl substituted with —Si(Y1)(Y2)(Y3);
• Y1 is a (C3-C40)hydrocarbyl;
• Y2 is a (C1-C40)hydrocarbyl;
• Y3 is a (C1-C40)hydrocarbyl, with the further proviso that Y1, Y2 and Y3 are not all isopropyl groups;
• and
• each of the hydrocarbyl, heterohydrocarbyl, Si(RC)3, Ge(RC)3, P(RP)2, N(RN)2, ORC, SRC, RCS(O)—, RCS(O)2—, (RC)2C═N—, RCOC(O)—,RCC(O)N(R)—, (RC)2NC(O)—, hydrocarbylene, and heterohydrocarbylene groups independently is unsubstituted or substituted with one or more RS substituents, each RS independently is a halogen atom, polyfluoro substitution, perfluoro substitution, unsubstituted (C1-C18)alkyl, F3C—, FCH2O—, F2HCO—, F3CO—, R3Si—, R3Ge—, RO—, RS—, RS(O)—, RS(O)2—, R2P—, R2N—, R2C═N—, NC—, RC(O)O—, ROC(O)—, RC(O)N(R)—, or R2NC(O)—, or two of the RS are taken together to form an unsubstituted (C1-C18)hydrocarbylene wherein each R independently is an unsubstituted (C1-C18)hydrocarbyl;
• and
• optionally two or more R groups of the R1-16 groups (for example, from R1-8, R9-16) can combine together into ring structures with such ring structures having from 2 to 50 atoms in the ring excluding any hydrogen atoms.