Catalyst systems and processes for producing polyethylene using the same

A process for producing an ethylene-based copolymer having a reverse comonomer distribution, the process comprising polymerizing ethylene and one or more (C3-C12)α-olefin comonomers in the presence a catalyst system in a single gas-phase polymerization reactor at a reactor temperature of 60° C. to less than or equal to 150° C. and a molar feed ratio of less than or equal to 0.020 of the one or more (C3-C12)α-olefin comonomers to the ethylene, wherein:

• the catalyst system comprises one or more support materials and an activated metal-ligand complex having a structure according to formula (Ia):
• wherein:
• A− is an anion;
• M is titanium, zirconium, or hafnium;
• n is 1, 2, or 3;
• each X is a monodentate ligand independently chosen from unsaturated (C2-C50)hydrocarbon, unsaturated (C2-C50)heterohydrocarbon, (C1-C50)hydrocarbyl, (C1-C50)heterohydrocarbyl, (C6-C50)aryl, (C4-C50)heteroaryl, halogen, —N(RN)2, and —N(RN)CORC;
• each Z is independently chosen from —O—, —S—, (C6-C50)aryl, (C4-C50)heteroaryl, N(C1-C40)hydrocarbyl, and P(C1-C40)hydrocarbyl;
• R1 and R16 are independently chosen from (C6-C50)aryl, (C4-C50)heteroaryl, (C1-C40)alkyl, (C3-C40)heteroalkyl, radicals having formula (II), radicals having formula (III), and radicals having formula (IV):
• wherein R31-35, R41-48, and R51-59 are independently chosen from —H, (C1-C50)hydrocarbyl, (C1-C50)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(RN)—, (RC)2NC(O)—, or halogen;
• R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, and R15 are independently chosen from —H, (C1-C50)hydrocarbyl, (C1-C50)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)—, and halogen;
• R17 and R18 are independently chosen from —(CRC2)m—, wherein subscript m is from 1 to 10;
• R19 and R20 are independently chosen from linear or branched (C1-C20)alkyl;
• and
• each RC, RP, and RN are independently chosen from —H, (C1-C50)hydrocarbyl, and (C1-C50)heterohydrocarbyl;
• and
• the ethylene-based copolymer has a unimodal molecular weight distribution as determined by gel permeation chromatography (GPC) and a molecular weight comonomer distribution index of greater than 0 as determined by determined by rapid Fourier Transform-Infrared (FT-IR) spectroscopy on dissolved copolymer during the gel permeation chromatography (GPC) measurement.