▎ 摘　　要

NOVELTY - Tridentate iron complex (I) is new. USE - (I) is useful in catalyst composition for catalytic polymerization of ethylene (claimed). ADVANTAGE - The method: achieves control of microscopic molecular structure by adjusting the polymerization conditions; and produces product with high catalytic activity, and excellent heat resistance. DETAILED DESCRIPTION - Tridentate iron complex of formula (I) is new. R1, R2= H, chloro, nitro, methyl, ethyl, propyl, isopropyl, phenyl, phenethyl-CHRPh or dibenzyl; R = H or 1-4C alkyl; and m and n = 1, 2, 3. INDEPENDENT CLAIMS are also included for: preparation of (I). upported iron catalyst composition, comprising tridentate iron complex and carrier, where the carrier is nano boron nitride, carbon nanotubes, and graphene. catalyst composition, comprising a main catalyst and a co-catalyst, where the main catalyst is supported iron catalyst. method for catalytic synthesis of polyethylene, comprising carrying out catalytic polymerization of ethylene using the catalyst composition.