Ethylene Insertion with Soluble Ziegler Catalysts: Direct Insight into the Reaction Using Enriched

The elementary processes involved in the polymerization of ethylene by soluble Ziegler catalysts of the type Cp2TiMeCl/AlMeCl2 have been studied by C N M R spectroscopy. Using Cenriched ethylene, detailed information was obtained directly on the system in the course of the polymerization. No spectroscopic evidence was found for precoordination of the monomer. The development of the oligomer distribution, which could be followed spectroscopically, proves that the mechanism proposed by Olive cannot be correct. These experiments show conclusively that the ethylene is inserted into the titanium-carbon bond.