<p>In this study, a series of iminopyridine ligands featuring electronically varied substituents (electron-donating or electron-withdrawing) and sterically modified diphenylmethyl groups (L1 ~ L6), along with their corresponding nickel catalysts (Ni1 ~ Ni6), were designed and characterized. These nickel complexes exhibited high activity in ethylene polymerization (up to 12.4 × 10⁶ g·mol^− 1·h^− 1), producing polyethylene waxes with molecular weights ranging from 1.2 × 10³ to 4.8 × 10³ g·mol^− 1. Furthermore, Ni4 ~ Ni6 can catalyze the copolymerization of ethylene and undecylenic acid to generate polar polyethylene waxes with molecular weights of 1.7 × 10³ to 3.6 × 10³ g·mol^− 1 with comonomer insertion ratios of 0.25% to 0.68%. Notably, increasing steric hindrance at the <i>ortho</i>-diphenylmethyl position and introducing electron-withdrawing substituents at the <i>para</i>-position significantly enhanced catalyst activity and thermal stability.</p> Graphical Abstract <p></p>