Camphor-based phosphine-carbonyl ligands for Ni catalyzed ethylene oligomerization

Abstract

Ni(II) and Pd(II) complexes of camphor-based phosphine-carbonyl ligands containing a biaryl moiety (L1 and L2) are designed, synthesized and characterized. The catalyst Ni1 exhibits high activities (up to 4.5 × 10⁶ g mol Ni⁻¹ h⁻¹) in ethylene oligomerization, generating waxy higher olefins derived from ethylene (M_n 2500–3500, T_m 99–120 °C) in the absence of a co-catalyst. The catalyst Ni2 also exhibits high activity (up to 4.4 × 10⁶ g mol Ni⁻¹ h⁻¹) in ethylene oligomerization, resulting in oily oligomers of ethylene containing a series of lower olefins characterized by GC and GC-MS analyses. No ethylene oligomer over C6 was obtained when using Pd1.