Multimetallic Catalysts for Chain-Transfer Olefin Oligomerization Aimed at Application to Lubricating Base Oils

Novel multimetallic catalytic systems that combine chain-propagation and chain-termination catalysts via zinc-mediated chain-transfer mechanisms have been developed for the controlled ethylene and ethylene/propylene one-stop (co)oligomerization. The pyridine diimine iron(II) dichloride ( 1 )–ZnEt 2 –camphor diimine ( 2 )–nickel(II) 2–ethylhexanoate catalytic system enabled the production of ethylene oligomers with controlled molecular weights ( M n = 940–1300 g/mol) and an exceptionally narrow distribution ( M w / M n = 1.2–1.3). Importantly, oligomers with such narrow dispersity minimize reactivity differences during hydro-isomerization, allowing efficient conversion into lubricants with uniform product properties. In the case of ethylene–propylene co-oligomerization, the dichloro[ rac -ethylenebis(indenyl)]zirconium(IV) ( 4 )–ZnEt 2 –pyridine diimine iron(II) dichloride (5) catalytic system produced transparent branched co-oligomers ( M n = 1600 g/mol, M w / M n = 2.3), which can be converted directly into lubricating oils by simple hydrogenation. MW reduction through chain-transfer reactions became significant in these systems, and further control was achieved by introducing chain-termination catalysts. The resulting oligomers have proper MW and branched structure for possibly converting to lubricating base oils.